Would you be willing to post code? It can be very difficult (read: impossible) to 

diagnose problems like this without the actual program.



I can assure you it is quite possible to overflow 1GB even with a few agents, 

especially if you're building networks. One place to look first is to ensure that you 

are not creating new network links between agents that already have links; you 

would probably want to modify link strength instead of creating multiple links.