Dp 4.6 Audio Settings, audio playback problem Options

[beauty_speed]

hi everyone,

I am new to DP 4.6, I am running it on a 1.67 g4 / 1.5Gb ram, Tascam us-122 interface.

I get an error message stating that the audio playback of what I have just recorded is overloading the processor , even when recording one audio track at a time, in a project with not more than 3 or 4 audio tracks.
The buffer settings are identical to the ones I use with Live 5, Reason, Garageband or Cubase yet I get this kind of messages and a much higher and annoying latency in DP whenever I try to play my instruments (virtual or external) live.

I have tried to play-disable and record-disable EVERY track except the one I am using but this does not seem to work either. I find it hard to believe that this has anything to do with the interface not being a MOTU...Even if the US122 is pretty weak it does allow me to work with every software I have tried out so far...

Thanks for any suggestions.