Max heap limited when running with a JVMTI agent?

Running an app with a JVMTI agent, I cannot specify a max heap greater than 320Mb, even on a 1Gb machine with hardly anything running. Specifying for example -Xms256m -Xmx512m results in following error:

Error occurred during initialization of VM

Could not reserve enough space for object heap

Could not create the Java virtual machine.

No problem at all with a JVMPI agent.

Anyone any ideas?

Thanks,

Luc

[453 byte] By [cfhlap0a] at [2007-10-3 1:21:18]