When the world editor is minimized or not the front process on the screen, does it sleep ?

I left the world editor trying to generate a 128X128 terrain last night, and of course the screen saver came on and the monitor shut off after 15 or 20 mins. The progress bar is exactly where I left it last night. When I bring it to the front and its the active process it runs -- otherwise it doesn't.

Is this on purpose ? And if so how can I make it run in the background when the window is minimized ?

is it Win or Mac? I've just tested it and it works ok for me (builds when window active/inactive/minimized)

TY for the prompt response: that problem was very weird -- I couldn't make it run unless it was the selected, open window; I like to have never got it to finish.

It's Windows 7 (64 bit) : Now that I know it's supposed to, I'm going to try it again. I made some new waypoints and stuff and I'm starting it now (Clean all, Build all), and see if it works minimized. I've never done a large terrain like that; so never had occasion to walk off and leave it. I'll test it again. OH, I was using the 64 bit editor (if that matters) Start time 1:46 pm my time .... I'll check again in a while and see how the minimized one functioned.

Worked just fine this time. I had thw window minimized. Took quite a while to complete (as expected), but i could see the processor time ticking away. No clue what was up the other time.