Updated to new firmware, now Avid AMA plays back poorly

[Brant Hadfield]

I was running the Beta firmware (first or second one with audio playback) with no problems for quite a while, several shoots. I probably shot 60 cards worth of R3D at 8:1, plus all the footage I've shot since getting the Scarlet in January, and Avid MC6 has played back the footage smoothly, no stutters, (in half res playback mode). Now, since updating to the new firmware, the R3Ds of any length stutter and are almost impossible to edit with via AMA. There have been no Mac OS updates, no Mac hardware changes, no Avid updates to our system. I have loaded R3Ds into a project shot before the Scarlet update, and the play back as smooth as ever. So something has happened since the firmware update. Anyone else? Any ideas? Red? Please don't tell me to transcode. I have been doing R3D Avid AMA smoothly since January until the latest Red firmware update.