Pointer jumps around when I use the trackpad on a UMBP

Hi,
I'm having a bit of a trackpad problem with my 15" Unibody. Sometimes when I use it, the pointer gets "stuck" and it takes a few swipes to get it to move.
When I try to use two-finger scroll, I have to scroll really fast just for the page to move a bit, and I have to swipe down at least 5 times before expose comes up. This problem seems to be intermittent, and started happening last night.

Anyone else having an issue with theirs?