I've just started 4-boxing, and I'm getting some odd behavior in that 1-2 windows will randomly stop accepting input .. they aren't frozen but they won't accept mouse of keyboard input. I can click away from them to one of the working active windows and those are fine, but the locked windows will stay that way for a good 10-20 seconds at a time, at least. I read a few others having similiar problems but couldn't find a solution that pertained to my situation.

If I didn't know better I'd think I was overloading my system, but I checked CPU and memory usage neither seem to be pegged.

I'm using ISBoxer.

My admittedly weak system specs:

AMD 3800 (Dual 2.0)
3 GB Ram
9800GTX+
WinXP Pro

1) Would I see a significant difference upgrading to 4GB and a quad core (likely a Phenom)?
2) Anyone experience the 1-2 window lockup / find a solution to this?