Unusually long pauses

My mill has been "pausing" for 3-7 seconds before some, but not all
G02 and G03 curves while cutting. I'm wondering why this is
happening. At first I thought that it was a problem with the
programming of the NC file, but after carefully studying them by
hand, I have found no apparent reason that it should.

A quick run-down of my computer:
PIII 850 with 512 MB RAM
Running DOS 6.2 and TurboCNC

I'm running Camtronics 600 oz.-in. servo motors and Gecko G320s.
Using a 36V, 20A Iota Power Supply

Does this sound like a hardware or a software problem? The NC files
appear to have no reason to pause, and the mill runs great with G00
and G01 codes, but sometimes in code that has G02 and/or G03 curves,
it has unusually long pauses, much longer than is needed to take up
the backlash in the leadscrews. Is my computer not fast enough to
run this? Do I need more "processing horsepower" to calculate the
movement for curves quickly?