The problem is in fact caused by the performance of your Tascam audio buffer handling. This is evidenced when you change the setting, the frequency of the pops and clicks increase or decrease. The Centrino processor is not an officially supported processor. Since it's a interface/driver performance issue, it's possible that the tascam driver is having issues running efficiently with the Centrino processor.

When you record, the audio data is recorded to your hard drive, not the RAM. I would be interesting to contact Tascam and see if they can recreate the performance issue and see if there's that could be done on their end to address the pops and clicks.