Issues with 3.0 upgrade

Recently I upgraded from 2.9x to 3.0 on all of my blogs. 85% upgraded perfectly without a hitch except for three. I am unable to access the admin on these three blogs. My password and/or user name is being rejected. When I use the “forgot password” function my email address is also rejected. I’ve tried everything but I continue to get the dreaded 3.0 wiggle. Is it possible to physically go into the WP program and see what the program has stored? Any help would be greatly appreciated.