well, if you can't find your model in the support...
Notice that Sony vaio laptop's usually have diferent model number, in the down right side of the screen, and diferent in the down side of the laptop...
i recomend after you have done this that you use a program called double driver
this will backup all drivers to a folder burn that and the program to a disk, that way you will allways have it on hand
laptop's are a pain when it comes to drivers becasue they usually never come with the drivers on a disk which makes re-installs a pain
I'm having the same problem with a Lenovo W520 (i7) laptop, running Win 7/64 with a Ricoh Firewire chip - sometimes works, but usually loses sync as soon as I start Nuendo. The Fireface 800 is not then recognized unless I reboot the computer.
My workaround is to use an expresscard Firewire adapter. The FF800 work fine. It is recognized the instant I plug it in, whether Nuendo is running or not. If I use the built-in Firewire, the FF800 will drop sync within a few seconds.