Provisioning has stopped working

vWorkspace 7.5, SQL 2008 ent, all servers Win2k8 X64 R2 SP1....

When expanding the number of workstations in a desktop pool nothing happens. The "Notifying connection broker" sticks on 80% for a little longer than normal but no error messages appear.

Likewise, when a user logs out of a VM, the VM is deleted but not re-created! - We're running out of VMs....

Oddly, creating a new group will create the specified number of VM's but then the issue above occurs - Currently using this as a work around and changing the desktop resource to point to the new pool.

We're using the rapid provisioning feature and Hyper-V for the desktop pools.

This started happening about 4 - 5 days ago. All brokers have been rebooted and hyper-v hosts re-initialized (they have also recently been rebooted).

Any ideas?

Dan