Haven't checked with pipelining, unless it's the same as link prefetching, but the later didn't make any difference when I tried it a couple of days ago and no luck today either. Might try it again though since I was a bit tired when I tried to fix this strange occurance. But since it happens to a lot of people I don't believe it's a mozilla thing, since most people still use msie. Also, it doesn't happen on all sites on my server with my mozilla...
Will check with a sniffer to see what requests are actually sent, to see if the problem is with my server or with the browser.