service packs are a roll-up of all prior updates, so you can install the OS then sp1 only, no need for other individual updates.
If after just these two installs, the same problem occurs then you will need to advise gigabyte of the problem.
If your really keen, you can even make yourself a new OS disc with sp1 integrated by using
Vlite, though there is one hideous 1.37Gb download of WAIK that you need to get from MS for vlite to work properly.
I've done it with my vista 32, works great, you can even tailor the OS to your liking
