Originally I reported this issue to ubuntu folks, and it is documented on the launchpad[1] but would like to bring this into attention also on this list.
Basically seems that on some occasions clock interrupts are not happening for longer periods of time causing that some VMs are crashing (i.e. Win7). More details including my sample application output are attached to launchpad bug report. Any help appreciated. Thanks, Damjan [1] https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1307473
