Debug build using more RAM than non-debug?

OK, here's another one which has me stumped. The debug build of my game takes up about 10mb less RAM than the non-debug version. Any reasons why this may be happening?

EDIT:

Woops! I worded that the opposite way! My debug version is actually using LESS ram than the non-debug build!

/brain fried from 10-day long programming session

The most reliable way to check mem usage is make your app windowed and have taskmanager open when starting it. Dont alt-tab from a full screen app.

That's what I've been doing.