I'm able to edit entries on my phone and have the edits go up to dropbox. Here's how I do it. It works every time for me.
1. Launch Dropbox app on phone. Within the Dropbox app, find the keepassdroid database file. Open the file from within the dropbox app.
2. Dropbox will download the latest copy of the file on my phone and automatically launch KeePassDroid.
3. The KeePassDroid app is open, I punch in my password. I edit existing entries, I add new entries, etc.
4. When I'm done, I hit the "Back" button on my phone to exit of out KeePassDroid. This drops me back into the Dropbox app, and I see that it has already uploaded the newly editted copy of the db file to the cloud.
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In the past, this has NOT worked for me:
1. Open dropbox app on phone. copy db file to some local folder on my phone.
2. launch KeePassDroid, browse to the local folder and open the copied db file.
3. Make edits, save file, exit KeePassDroid.
4. Copy editted db file from local folder to the dropbox folder.
Dropbox never pushs the editted file (that I copied into the dropbox folder in step 4) up to the cloud.
Good luck.
Tom