Happy New Year everyone!
Just a note in case you missed it. I updated the List Uploads (q2a Image Manager) plugin, see: http://www.question2answer.org/qa/18768/new-plugin-list-all-uploads-v0-5-update-q2a-image-manager
In version 0.4 the default avatar got deleted if you clicked "Remove all unused images from database", as its usage/location was within table qa_options.
The new version 0.5 is considering this, and also checking all custom pages for the usage of a blobid.
Have a good start!