I downloaded the ALPS driver from Sony's Vista page, installed it (despite Windows's warning that "you are already using the optimal driver for this hardware"). After doing so, the touchpad doesn't respond at all, and I had to resort to using the keyboard to rollback the driver to the one that came with the os.
I've tried both versions 7.0.501.5 and 7.0.502.5.1 with the same result.
Anyone with better luck?
Staffan