I have both Ultimate 64 and 32 on dual boot on my computer.
While I was exclusively on 64, I noticed that anything created with Photostory 3, and old stories in .wmv format were playing badly in WMP 11. The image was bouncy during all transitions, and the audio was sometimes of bad quality.
I thought that maybe it would just be the playback, but anything imported in Movie Maker and transformed to DVD kept that "bouncing around"...
Since then, I reformatted and did a clean install of both systems. On the 32 bit version I have no problems with playing, and creating Photo Stories. I have smooth playback. I can also import avi files in Movie Maker with no problems. I checked that right after the installation of Windows, and also after installation of all updated and new drivers.
On the 64 bit version, right off the bat after installation, I cannot have smooth playback of Photo Stories, but DVD playback is fine. I cannot import avi files in Movie Maker (only audio, black screen). Even after installation of all updates and updated drivers for everything, it does not get better.
So it may not be a driver issue, as with nothing else installed than Windows, it does not work properly at first login under 64, but does on 32.
The only thing in BIOS which I thought could do a difference was the HPET mode (32 or 64 bit) but that didn't do anything.
The videos are located on a NTFS partition (d: ) of the system hard drive (c: ).
I'm quite disappointed with vista x64, which I hoped I could use. 2 problems that are only on 64, not on 32 : bouncy playback of .wmv and avi import in Movie Maker fail.
My specs (on 32 bit for now, 64 installed with no drivers) :
MSI NX 8600GT-T2D256E OC (with latest Nvidia Drivers)
GA-P35-DS3L mobo, with latest Bios F5
Intel Core 2 Duo E6750 @ 2.66 Ghz
Realtek onboard HD audio, with latest drivers 1.8
Realtek onbaord LAN, with latest driver
2 x 1 GB OCZ XTC Rev 2 at 4-4-4-15