Here's some interesting reading about how horrible a company Creative really is:
"Creative Goes After Driver Modder"
"Creative Vista Driver Modder Speaks Out"
"Creative Backs Down on Vista Driver Debacle"
btw: this is all concerning the person who created the drivers you linked "daniel_k"
The short version is that Creative has said on record that for various reasons that most, if not all, the advanced features of their cards are not supported under windows vista. Daniel_K modded their drivers and made virtually all of those functions work (and work properly). Creative didn't like the fact that the things they had purposely disabled under vista were now working, and no longer forced people to buy newer sound cards from them, so they tried to punish daniel_k. The public supported daniel_k, and creative has hurt their business. Creative buckled and now is supporting daniel_k and his modded drivers.
ps: Creative has sold their HQ, and looks to be on the road to bankruptcy.