I was having strange lockups and the occasional bluescreens with my Asus A7V333 and WinXP Pro. On AMDmb.com I read a few peeps that claimed that you really don't need VIA's 4in1 updated drivers, especially if you upgraded to SP1 (there is a VIA update in SP1).
I was sceptical, but nevertheless at my next reinstall I did not use any VIA 4in1's and have not had a single lockup or blue screen in 3 months. Oh and yes, I installed SP1.
As for the Windows Update problem..... this happened just after you updated VIA 4in1's? Are you sure there were any updates available?