Weird problems with smaller window resizing.

This isn't solely a Marketpress question as much as a Gridmarket question. But I have a problem with my category sidebar pushing over to overlap my products on the product list. I've run multiple tests trying to emulate the problem on my computer but can't seem to find the root of the problem.

Is there any workaround to fix this? Or is this something that just happens with Gridmarket on lower resolution computers, the computer that sees this problem is a PC laptop with a very small screen, not sure the exact specs or resolution and they are using firefox.

I'm sort of guessing it's a problem with the sidebar since it also had the same problem of the checkout page.

Any help would be very appreciated.

http://i.imgur.com/2NQteWI.png

http://i.imgur.com/IE8MrrR.png