diff --git a/app/scripts/comp/dropbox-link.js b/app/scripts/comp/dropbox-link.js
index 6b514810..d26d8698 100644
--- a/app/scripts/comp/dropbox-link.js
+++ b/app/scripts/comp/dropbox-link.js
@@ -239,9 +239,10 @@ var DropboxLink = {
         Dropbox.AuthDriver.Popup.oauthReceiver();
     },
 
-    saveFile: function(fileName, data, overwrite, complete) {
-        if (overwrite) {
-            this._callAndHandleError('writeFile', [fileName, data], complete);
+    saveFile: function(fileName, data, rev, complete) {
+        if (rev) {
+            var opts = typeof rev === 'string' ? { lastVersionTag: rev } : undefined;
+            this._callAndHandleError('writeFile', [fileName, data, opts], complete);
         } else {
             this.getFileList((function(err, files) {
                 if (err) { return complete(err); }
diff --git a/app/scripts/models/app-model.js b/app/scripts/models/app-model.js
index 2f55dadd..bdbc0fb4 100644
--- a/app/scripts/models/app-model.js
+++ b/app/scripts/models/app-model.js
@@ -318,7 +318,7 @@ var AppModel = Backbone.Model.extend({
                 return callback('Duplicate file id');
             }
             var cacheId = fileInfo && fileInfo.id || IdGenerator.uuid();
-            if (updateCacheOnSuccess) {
+            if (updateCacheOnSuccess && params.storage !== 'file') {
                 Storage.cache.save(cacheId, params.fileData, function(err) {
                     if (err && !params.storage) {
                         return;
@@ -361,6 +361,89 @@ var AppModel = Backbone.Model.extend({
         if (file.get('syncing')) {
             return callback('Sync in progress');
         }
+        // todo: save to cache
+        var fileInfo = this.fileInfos.getMatch(file.get('storage'), file.get('name'), file.get('path'));
+        if (!fileInfo) {
+            var dt = new Date();
+            fileInfo = new FileInfoModel({
+                id: IdGenerator.uuid(),
+                name: file.get('name'),
+                storage: file.get('storage'),
+                path: file.get('path'),
+                modified: file.get('modified'),
+                editState: null,
+                rev: null,
+                pullDate: dt,
+                openDate: dt
+            });
+        }
+        var storage = Storage[options.storage || file.get('storage')];
+        if (!storage) {
+            if (!file.get('modified')) {
+                return callback();
+            }
+            file.getData(function(data, err) {
+                if (err) { return callback(err); }
+                Storage.cache.save(fileInfo.id, data, function(err) {
+                    callback(err);
+                });
+            });
+        } else {
+            var maxLoadLoops = 3, loadLoops = 0;
+            var loadFromStorageAndMerge = function() {
+                if (++loadLoops === maxLoadLoops) {
+                    return callback('Too many load attempts, please try again later');
+                }
+                storage.load(file.get('path'), function(err, data, stat) {
+                    if (err) { return callback(err); }
+                    file.merge(data, function(err) {
+                        if (err) { return callback(err); }
+                        if (stat && stat.rev) {
+                            fileInfo.set('rev', stat.rev);
+                        }
+                        if (file.get('modified')) {
+                            saveToStorage();
+                        } else {
+                            callback();
+                        }
+                    });
+                });
+            };
+            var saveToStorage = function() {
+                file.getData(function(data, err) {
+                    if (err) { return callback(err); }
+                    storage.save(file.get('path'), data, function(err) {
+                        if (err && err.revConflict) {
+                            loadFromStorageAndMerge();
+                        } else if (err) {
+                            callback(err);
+                        } else {
+                            if (storage === Storage.file) {
+                                Storage.cache.remove(fileInfo.id);
+                            }
+                            callback();
+                        }
+                    }, fileInfo.get('rev'));
+                });
+            };
+            if (options.reload) {
+                loadFromStorageAndMerge();
+            } else if (storage === Storage.file) {
+                if (file.get('modified')) {
+                    saveToStorage();
+                } else {
+                    callback();
+                }
+            } else {
+                storage.stat(file.get('path'), function (err, stat) {
+                    if (stat.rev === fileInfo.get('rev')) {
+                        saveToStorage();
+                    } else {
+                        loadFromStorageAndMerge();
+                    }
+                });
+            }
+        }
     }
 });
 
diff --git a/app/scripts/models/file-model.js b/app/scripts/models/file-model.js
index 0555ee90..5471c760 100644
--- a/app/scripts/models/file-model.js
+++ b/app/scripts/models/file-model.js
@@ -3,7 +3,6 @@
 var Backbone = require('backbone'),
     GroupCollection = require('../collections/group-collection'),
     GroupModel = require('./group-model'),
-    Storage = require('../storage'),
     IconUrl = require('../util/icon-url'),
     kdbxweb = require('kdbxweb'),
     demoFileData = require('base64!../../resources/Demo.kdbx');
@@ -29,7 +28,6 @@ var FileModel = Backbone.Model.extend({
     },
 
     db: null,
-    data: null,
     entryMap: null,
     groupMap: null,
 
@@ -157,6 +155,18 @@ var FileModel = Backbone.Model.extend({
         this.trigger('reload', this);
     },
 
+    merge: function(fileData, callback) {
+        kdbxweb.Kdbx.load(fileData, this.db.credentials, (function(remoteDb, err) {
+            if (err) {
+                console.error('Error opening file to merge', err.code, err.message, err);
+            } else {
+                this.db.merge(remoteDb);
+                this.reload();
+            }
+            callback(err);
+        }).bind(this));
+    },
+
     close: function() {
         this.set({
             keyFileName: '',
@@ -221,8 +231,13 @@ var FileModel = Backbone.Model.extend({
             historyRules: true,
             customIcons: true
         });
-        this.data = this.db.save(cb);
-        return this.data;
+        var that = this;
+        this.db.save(function(data, err) {
+            if (err) {
+                console.error('Error saving file', that.get('name'), err);
+            }
+            cb(data, err);
+        });
     },
 
     getXml: function(cb) {
diff --git a/app/scripts/storage/storage-dropbox.js b/app/scripts/storage/storage-dropbox.js
index a79d3d72..5ad01695 100644
--- a/app/scripts/storage/storage-dropbox.js
+++ b/app/scripts/storage/storage-dropbox.js
@@ -18,8 +18,8 @@ var StorageDropbox = {
         });
     },
 
-    save: function(path, data, callback) {
-        DropboxLink.saveFile(path, data, true, callback || _.noop);
+    save: function(path, data, callback, rev) {
+        DropboxLink.saveFile(path, data, rev, callback || _.noop);
     }
 };