Hi,
First get EasyFind...
http://www.versiontracker.com/dyn/moreinfo/macosx/8707
You can find, move, delete hidden files.
Then Safe Boot from the HD, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, it will try to repair your Disk Directory while the spinning radian is happening, so let it go.
Trash this file...
/Users/YourUserName/Library/Preferences/com.apple.Preview.plist
Move or trash that gif file with easyfind if you wish.
Check that Preview isn't in System Preferences>Accounts>Login Items window.
Reboot.