Disappearing addins with WML 8

It seems that once you uninstall Messenger 8 add ins, you can never get it
reinstalled properly. I cannot get the weather button or the Pshing add in
to reappear. When I try to reinstall I get an error that it cannot read a
file in temporary internet files. I am ready to reformat and reinstall
because I think it has screwed up other things on my system.

Anyone get the add ins reinstalled after you do an uninstall?