Yeah, I've been noticing terrible problems with eBay and safari lately as well. It doesn't quit on my, but hangs up when loading every page, and progressively gets worse. If I open Activity Monitor after searching on eBay for maybe 30 minutes or so, AM shows Safari using almost 100% CPU when it is loading pages, and shows "safari hung" for 5 seconds or so with each page load. Plus, it shows very high memory usage, such as 600+MB of real memory and over a gig of virtual memory. (Both figures continually rise while surfing...) I see tons of beach ball on eBay, but it never jut plain quits, at least not yet.
I'm using a new 1.5ghz powerbook with 2 gigs of RAM, on a high-speed network. Page loads should be instant with a setup like this, to say the least! All this beach ball and slow eBaying makes it feel like I'm using my old 266mhz pentium II to surf the net with a 28.8 modem on a bad day...
(Yes, I've repaied permissions, ran man janitor, cleared the cache, etc...) Restarting Safari helps, but it just gets more and more bogged down with time.