This will sound very strange, but now I'm convinced that this is actually happening. I noticed that search engine bots kick each other one out, sometimes I see google bot being kickout out by yahoo bot and yahoo bot kicking out google bot. It seem like my website only allows one ip address without session id at a time. I started looking into this after I noticed that my indexing in yahoo and msn are extreamly slow.
I also have a program that has search engine spider simulator built in, so when I try to access my site with it, I see google bot disappears, but then it comes back after few minutes. This is pretty bad for my site, please help somebody.
The site is hosted on Xampp for windows on windows server 2003 standard.