Ok,
- Pictures don't disappear for no reason - i.e. a change has happened.
- What guidance did you follow that stated that uninstalling and reinstalling would solve the problem?
- Has the URL to the site changed in any way?
- Is the URL to the site public?
- Please list in fine detail exactly all the changes you have made to both the theme and core code from the download originals?
- What other contributed plugins do you have installed?
- What web browsers and versions are you using?