PiP problem

My last thread got moved to completely wrong section, but I've done more testing since then anyway so I decided to edit it so it can die/be deleted and create a new one!

First thing first, my rig;
Q6600
8800GTX
4GB DDR2 800MHz
Raptor 10k rpm
Maxtor 7.2k rpm

I run five instances of WoW with this computer and for now I only have one monitor.
Playing in fullscreen I get 60 steady fps with everything on highest details, but in Windowed Mode it drops significantly. That being said I've tweaked and changed settings until I reached a comfortable fps in Windowed Mode aswell (60 most of the time).
Now the problem is that I then set everything up via Maximizer since I want to use the PiP function because without it it's pointless trying to switch to a slave (takes too much time, especially for PvP in the future), so I set the four slaves to share equal space of the entire space (1680x1050) and then my main ontop of those taking up the whole space.
This seemed to work fairly well until I actually used the PiP function, what happens is that the last used window (the last slave before I switch back to my main) doesn't get set as "running in background" but instead runs as an active window together with my main window, it doesn't put itself ontop of the main window but because it is no longer "in the background" it tries to use 60fps and it kills the fps on my main.
Sometimes more than one slave window behave this way and at one point I actually had all of them running as active and I had 12fps on my main.
What I then did was I put all my slaves to 420x131 on the bottom of the screen and found a solution; whenever this happens I just move my mouse over to the window that isn't running in the background and then back onto my main window and it fixes itself.
But since I want to get myself another monitor I'm assuming this problem will still exist then and when those windows are in the background of my main I can't do the "mouse trick" to fix it, which means I can't use it which in turn means a big resounding f-word for me. :(

Any idea on how to fix this?

Yes, set up maximizer and PIP correctly. I read this as: you only have your main window viewable, unless you switch. Do some research on how other ppl have set up PiP- they have crunched calculations on window sizes and everything.

I'm sorry but that didn't make much sense to me.
I fail to see how I have not set it up correctly, I've done it both ways; having all windows visible on the same monitor and having four in the background and the main ontop.
The latter shouldn't be a faulty way either since there even is a function "always on top" in the software to allow for this.
And as far as calculation crunching going I'm note sure what you're referring to but obviously I set them all up to correct sizes so they didn't overlap if that might be what you meant.