Make ignore ignore threads started by people on the ignore list
Sometimes it can be fun to talk about strange things, but not with people who you know it's pointless to talk to.
Especially irritating with the guys who make tons of ridiculous threads which they then don't respond to.
not good with computers
IIRC threads by ignored users showing up is a vbulletin design choice, not something we can change.
Stood in the Fire
I've seen it done on other forums, but I grant that may be due to vBulletin hacks and mods that you might very well not wish to entertain on a site of this size.