god knows.... also i not able to connect throw access 2007 file using x64 xp or 2003 using visual studio 2008 beta 2. but in x86 mode it working fine.
some of problem i see in x64 xp. like after installing sp2 for x64. the x64 sp2 file is one for 2003 and xp both.

after installing sp2 i get some mode option in windows component and when i try to install those they asking me for 2003 x64 cd. i'm using xp and it ask me for 2003 cd.

in xp x64 sp2 after installig wmp 11 or default wmp i not able to use start menu toolbar such as wmp toolbar that looks coolz.
also, there is context menu problem, after installing cuteftp or ccleaner etc. i not found those option in xp x64 context menu.
and much more bugs, like multitasking suck in quad-core processor(maybe it need octal processor

). it use more ram(let it go cause my pc run fast now.).
in x64 i get some improvement in 3ds max, maya, jre, .net application etc. but still have problem with compatibility.
i think our next generation's computer will x64 based not x86 anymore. and new driver, games, software work well in x64 edition. but i think Microsoft need to update xp x64 bugs and fix those. they only publish sp1, sp2, sp3, sp4 etc. but not fix some bugs in x64. ya sure x86 work good without bugs.
but after installing some about 350 program x86 can't handle registry it sucks. and some time start menu etc not shown. but in x64 i installed more than 430 application, games etc in my 500gb westerb digital hdd with 2gb ram. os run very smooth with avast antivirus and windows defender, sql server 2005 express, oracle.
borg where i post Microsoft os bugs. how to contact with them about bugs (some ms guy really bored. i faced a problem with installing aom in vista x64. they say format etc. but when i call us support center they fix my problem in 15 min, where indian ms tech center tech 2 hour on phone :x).. i purchased xp x64 2months ago..... and i not want to call that tech center anymore, is there any email address or forum for microsoft os bug post etc?