KVM host OS restarts when loading the guest OS


I want to setup KVM virtualization on my laptop Dell Inspiron 1526 (AMD64 Turion, 2GB RAM)
running Ubuntu 9.04 kernel 2.6.28 and KVM-84 (the latest official versions supported by Ubuntu)

I can successfully create an image file using:

but when I’m trying to start a virtual machine:

the host os restarts when the guest os starts loading.

I’ve checked the logs, there are no useful messages, only something like kvm module loaded, and
enabling/disabling virtualization on CPUx

Can anyone help me with this issue?