High memory usage with OpManager and java.exe

I'm using OpManager v.7204 and java.exe is consistently using a very large of memory. What will happen, is after restarting OpManager, the memory usage on java.exe will start out low, as you would expect, then after approximately one week, it'll slowly increase, easily reaching 1.5GB of memory, and this on a server having 2GB total memory.

We do have the monitoring intervals sat rather low, but we hate to increase this as OpManager's monitoring our production environment, which we need to respond to immediately when having any issues.

Is there any other way to limit the amount of memory java.exe consumes? I'm using whatever version of Java came with OpManager v.7204

Thanks in advance for any help.