Thanks for the help guys. My bulb kept cycling off yesterday...it would ignite then shut down after about 30min to an hour. Was hoping it was the bulb...afraid it was the ballast after talking to Cris at aquatic art.
As it turns out, the jbj nanocube hood has a built in thermal switch that shuts the light off if the temp gets too high in there. Went to replace the bulb yesterday and the ceramic fitting at one end of the bulb was cracked. Not sure if overheating caused it to crack, or vice versa, but that seemed to be the issue. Got a bulb in there temporarily (thanks Cris!) and everything seems to be back to normal.