Panthro - 5:03 pm on Jul 12, 2013 (gmt 0)
Check what settings you have in StatCounter for "Idle Time Between Visits". Should be under your Project > Config > Project Settings. Make sure it's set to at least 1 hour (set to 30min by default).
Also, StatCounter tallies bot visits along with all other unique visits unless you elect to not show those in your logs, which they recently made it very easy to do.
Overall, I've always seen a pretty regular disparity between the visits GA and StatCounter shows. I've found the real number is usually somewhere in between the two.