Two ways:
#1 - When you go to the vbProArcade admin panel it will echo a line at the top right now saying something like "safeupload is 1" if it says 1 you are in Safe Mode, otherwise you're not.
#2 - If icons/thumbnails are working, you're probably not in safe mode.
I have servers up the ying-yang, but all my vhosts are in normal mode, and my dedicated box I can't change because I am running scripts that are dependant on it *not* being in safe mode.