That seemed to be the issue, Jafula, thanks!

I took the StaticPopup_Hide("PARTY_INVITE") and put it into another macro and the accept macro works fine.

It is odd that that macro worked just fine until 4.0.1 and it is a bit of a bummer to have to hit two keys to do what only required one before, but I'm happy for a solution to something I use 12 times a day

BTW, there isn't any way to add a delay within a macro so I could keep it to one key, is there?