i don't think it's pip, as the maxfps and maxfpsbk are set when wow starts up.

if the fps drops to 5 fps, that's telling me the system is getting crushed and is only able to get 5 fps for some reason. i would check the fps on the other windows. are 2 or 3 of them getting the maxfps? that would leave very little for the others.

i find if i mouse over with mouse-click-passing on (or just click on each wow), it seems to force wow to figure out that it should dial up to maxfps .. then dial down to maxfpsbk when you click off.