I've been off and online today doing auctions.
I just checked approximately 30 of my auctions...images are there and have been in my auctions every time I've looked.
Sorry you're having this problem.
It helps to have a link so others can view the auctions your having problems with.
You clear your cache once a week?
Gosh, I clear cache, history and more at least twice a day.
This is a fast solution
http://www.tucows.com/preview/363457and I use this one, too for getting rid of the .dat files and more from all of my browsers at once.
http://www.ccleaner.com/Hope these help you!
Donna