Vista - Unusual Problem

i have 64 bit vista installed and just noticed a weird issue (well not sure if its a big one or not) but trying to fiqure out why when i install 64 bit applications they install in the x86 folder and report as installed as 32 bit in the programs help section. i thoughty maybe it was this one application (the beta of mozilla's x64 firefox browser) but i installed another 64 bit application from nvidia for physx control of my video card, and that installed as 32 bit as well, what can be causing this? i did install the beta to sp2 on this machine a few days ago, and cant remember if this issue was pre or post that install. i have used EVEREST premium and it reports:
OS Name Microsoft Windows Vista Ultimate
OS Code Name Longhorn Server
OS Kernel Type Multiprocessor Free (64-bit)
OS Version 6.0.6002

Any replys, or help would be greatly appreciated, ty

In the case of the Physx install it is probably because it is used by both 32 bit and 64 bit games (that support it). The 64 bit Firefox is still in beta and that is probably just one of those things they need to adjust in the installer somewhere along the way.