Good to know the problem is fixed. However, I'd advise against using 0 for the memory limit in a production question because a memory gobbling submission might then be able to cripple Jobe. It's safer to find a value at which a typical submission will run OK and then, say, double it.
I'm also curious as to why your Jobe server seems more prone to memory limit problems than ours. Are you perhaps running it on a 32-bit OS?