I use Opera 10.5+ as my main browser(s) (2 versions...the one they called 'Unite' and newer one with the redesigned toolbars and access to tools)... they work fine.

Now, I do know that 'some' sites treat Opera as an orphan step-child and do not...umm... 'support' it. But Opera is in better compliance with official wes standards than I.E. or others....it's just that they design the sites to fit IE and Firefox. Perhaps that is the issue with eBay... I almost never use eBay...so... *shrug*