ive ran mine for the last couple months and its been 24/7
just a normal computer, not that great, nothing special really.
it stays at 36-41 degrees C (thats what it says on the front)
so i guess as long as it doesnt get too hot, then ur ok.
also, the way i judge when it needs a reboot,
i go into task manager, and i click on the "performance" tab, and if the "PF Useage History" is almost full, its time for a restart. (mine goes to 3.6 gb urs might go higher/lower).
ive noticed that when the PF useage gets completly full it will turn off (crash)