I've noticed that my traces in my thermalling are showing 90-degree turns and "jags" that just don't seem to mimic thermals I fly. I'll admit that sometimes my thermals are not perfect

but I'm pretty sure I'm not flying them the way they look on the replay! I've tried changing the logging from 1 to 3 seconds without seeing much of a difference.
I'm running SeeYou on a iPAQ310. Are there any other settings to consider that might resolve this?
Thanks,
John