[Fedora-xen] kvm memory corruption?

[William Murray]

  Hello there,
            I have a VM installed in Fedora 10 with the virt-manager 
gui. Its
great! I love the fact I can mount disks so guest and host can both see 
them.
But..I created it with 1-2GB ram (from my total 4), and it defaults to 1GB.
That works. If I increase it to 2 I start to see weird crashes in the host.
 
   How can I migrate this system to having always 2GB please?
---and safely!

            Thank you,
             Bill