VM crashes with OOM in the console log

Hi,
I have a cluster of Ubuntu9.04 servers using KVM and running virtual instances managed by Eucalyptus. When some java process is using a lot of memory in the VM, it crashes giving Out of Memory error in the console.log file of the VM.

My KVM version on Ubuntu 9.04 is 0.84 . Are there any known issues with this version of KVM ? Any pointers to debugging this further ?

Thanks,
Sagar