I have my old 6800 which is still in great condition, but while doing some experimenting with it, I messed up my radio settings. I can no longer receive a signal from the towers. So this will inhibit my ability to test things for you. I will, however, see if I can find anthing out in my settings that might help you. Are you running the Stock WM 6.1 (MR1) or WM 6.1 (MR2) ?
I have Stock (MR2) which I can flash to in order to do some testing, but I no longer have MR1 files.
The arcsoft is indeed for MMS, but it does both, and sometimes it will bring forth more settings. I have used various arcsoft setups and found quite a bit of differences.
I could be wrong in this, though, as it is still kind of an assumption, and you know what they say about ASS(of)U(&)ME(ing) things.