GacUtil Installation Failing w/ RC1

Has anyone had this problem before? On an administrative account (both the original account and a different account that I created that is part of the 'Administrators' group), trying to run "gacutil -i <somename>.dll" fails saying "...access denied. You might not have administrative credentials...". I installed Vista RC1 and immediately afterwards installed VisualStudio 2005, though if there are special Vista-specific patches, I am not aware of them.

[497 byte] By [Tencntraze] at [2007-12-24]