your aspect ratios seem to be off a bit.

after you hide the task bar, try setting the dimensions like this:

big regions = 840 x 630
smaller regions = 560 x 420

i got those magic numbers by solving the following for h:

840 / (1050 - h) = 560 / h

i could post the max file, but i'm not able to at the moment (at work)... hopefully that will be enough

if you got it right, the minimaps should be perfect circles.

also, set your game resolutions to 840 x 630.. this will insure proper aspect ratios when you pip swap