i recently acquired virusbarrier x5 through macHeist for free. It must have worked great for a couple of weeks if i remember correctly, but then i started getting apparently random kernel panics anywhere from 1-4 times a day. honestly, i hadn't noticed if they were in relation to VBx5 scans, so it didn't occur to me that it might be a problem until i uninstalled about 3 other (and more recently installed) programs.
I finally just uninstalled it about 20 minutes ago, and now that i see there are known snow leopard issues, i'm hopeful i finally have it taken care of.
I'm just glad i don't have to fight the company for my money back.