I have encountered this problem also (not able to minimize IMGBurn). Using v126.96.36.199 with WinXP SP2. Doesn't do it all the time. Only seems to happen after I burn a DVD containing AVIs and I get that message about correcting the filesystem. I always click "NO". I leave it at ISO9660 + UDF. I have always used that and have never had a problem. v188.8.131.52 is the first time I've had the message pop up (upgraded from 184.108.40.206 -> 220.127.116.11). I click on "Calculate Image Size" after adding all AVIs and get that message about changing filesystem. Then when I burn I get the message again. Always click "NO". Sometimes IMGBurn will freeze up after a similar burn or two. When I click on any part of IMGBurn window I get an error sound (same as when you try to click on a window in the background that cannot be accessed until an active window is closed. I have to kill IMGBurn in task manager.