Some bits of important inforation missing.
Firstly, I'm guessing, but I'd assume that the PreSonus IS working OK, it's just the Roland that is NOT.
Is the Roland working on it's own, as far as you can tell?
How have you got the keyboards connected, and into the computer? Are they connected side-by-side, or do you plug one into the other, then the other into the computer. I assume you're using a USB connector of some sort, which connector, there are some 'problem' ones about.
This information will at least be a start!