Question: Memory limitation - running maple.java from Linux Ubuntu workstation

I have been running up against a memory limitation when running maple.java v15 from a Linux Ubuntu workstation.  The memory indicator in Maple gets up to 39.36M but will not go above that.  After I reach this limit I am still able to perform further computations but Maple gets slow and eventually crashes.  Here is one of the lines from the error message:

Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: GC overhead limit exceeded

I have tried to increase the usable memory for Maple by trying the following two commands to launch Maple;

1) maple.java -T ,500000,,

2) maple.java -Xmx512m

These did not effect the 39.36M limit though.  The machine I am using has 4GB of RAM.  While what I am asking Maple to do is certainly complicated, I think it's reasonable and might run fine if I can increase the memory a bit.    Any suggestions on how to do that would be greatly appreciated.