Pro Tools Update 9.0.5 Help! Midi Killed

[edisonmusic]

I updated to Pro Tools 9.0.5 yesterday. I am running OSX 10.6.8. Midi is not working correctly. I have a Yamaha Controller hooked by USB to the Mac. If I make an instrument track with the plug in and play the keyboard I see nothing (usually there's an indicator of midi activity). When I record on the track notes appear but the plug in does not react i.e. no sound. On playback the midi notes I just recorded play on the plug in.

I have trashed the prefs, downloaded the latest midi driver from Avid, tried removing plug ins (I did update a few that were causing other troubles namely Flux and Isotope). The Audio-Midi driver shows the correct midi setup including my interfaces. Please help! I need midi to work.