jpr28056 - Welcome to the Board
The behaviour you experience is not as it should be - I cannot reproduce it in IE7/XP Pro on eBay.
I am not a Vista user, but have not seen mention of this before so have no idea if this problem is Vista specific.
Do you keep your temporary internet files cleared out? .....
Tools > Internet options > Advanced and scroll down to 'empty temporary internet files when browser is closed'.
It may be that an add-on is causing this problem - disable them all through Tools > Manage Add-ons and test. If the problem is resolved re-enable one by one testing each time until the culprit is found.