The driver problem is discussed at KB948343. Presence of these drivers (in particular Sigamatel Audio and Upec biometric) will prevent the instalation of Vista SP1 Via Windows update.
In the event you want to install updated drivers, I have found the following drivers: at:
ftp://ftp.vaio-link.com/PUB/VAIO/ORIGINAL/
For Upek:SZ7_FINGERPRINT_SENSORDRIVER.ZIP
For Sigmatel:AR6_AUDIO_DRIVER2.ZIP
I installed these on my SZ330 this evening. The Upek looks like a pretty safe bet as it is only one file. The Sigmatel driver is a whole different thing, but it appears to be working without issue. A few days testing will tell. Both drivers installed without errors. Actually, the older drivers mentioned in KB948343 appeared to be working, but reading that article put me on notice.