I have been using 126.96.36.199 64bit XP driver with Vista64 and it seemed to be fine until i tried a 2GB SD card - it wouldn't recognise it properly and had ghost files on it after formatting (some space used up).
I found a 64bit driver of 188.8.131.52 which works flawlessly now with Vista64 and ReadyBoost works correctly on my 2GB SD. I'm not sure if there are later (184.108.40.206 seems to be the latest 32bit driver) but it seems a lot of manufacturers are behind in creating a 64-bit driver for this device...
You can find it here http://www.bouncingtigger.net/techstuff/dv5210/
Many thanks to the hoster - that file means i now have a perfect Vista64 install on my Ferrari 4005 WLMI