Man, it was wierd yesterday with this issue. Mason, I too had it working now and then with the 'Task Manager/Switch To' button. It would work, and sometimes not.
If I paused the sim, then Alt-Tab out, I could sometimes Alt-Tab back in, but rarely.
If I 'Switched Too' about two to three times, I could get back in, but not every time.
A couple of times, it allowed me to Alt-Tab back in.
I did update my drivers on my vid card the other week, so perhaps this is an issue. Reason I say this, is even though I could Alt-Tab back in, when I Alt-Tab back out again, there would be a huge black area taking up 50% of my screen, and moving program windows around didnt bring the black area back, so I still had to turn off FSX in order to view/modify airplane configs and use Gmax, etc.
Man, I would sure love to tackle this beast that has krept in...
arrghh..
Bill