OGL has v-sync support now so if you seem to be locked on a FPS of 60, 75, 85, etc. then make sure to run with -no_vsync and see if that fixes it. There is also a "MaxFPS" registry option which can restrict the FPS to a maximum number if you wish (if you don't/can't use v-sync and wish a specific max FPS).
Task switching related stuff is still in progress. The thing is that constantly minimizing the game is getting on everyone's nerve's, so it can just jump to a window now. It needs a little more work to the events so that for certain things it can still go minimized rather than to a window. After that it should jump to a window if it's a game related message, and go minimized if it's a system related event message (like task switching).