HKLM\SYSTEM\MountedDevices Fully Qualified Name different between 32 and 64 bit Windows 7

Question

I am attempting to resolve a drive letter from a found usb mass storage device via VID and PID. To make this magical connection, I was using the following registry key:

Computer\HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices

In 32bit versions of windows, the data contained within (for example) \DosDevices\F: is the following:

"STORAGE\REMOVABLEMEDIA\9&A605B48&0&RM", which happens to be the volume device ID

In 64bit versions of windows, I do not get the same data:

in hex: "00 73 B5 A4 00 7E 00 00 00 00 00 00" Garbage.

Any idea why I'm getting different results between 32 and 64bit versions of windows here?