I'm using 2 servers, both configured same, tried in many browsers (opera, ffx, safari, ie9, chrome)
-on my 32 bit server everything is fine sessionid matches the cookies values
-on my 64 bit server the sessionid differs from the cookie value (but they created at the same time)
(if I manually change the cookies value (from ffx webdev toolbar) to match the sessionid everything works fine until it expires or the session ends)
I'm using 64-bit server on Athlon X2 CPU, and Debian 6.0.1 OS, having the same problem of not matching SESSION_ID, after loading system with 32-bit kernel, problem still persist.