"Migrate to Server" menu item not present for VMs in 6.5 pool.

I have 2 pools. Both were running a fully patched 6.5 SP1. I upgraded 1 pool to Dundee Beta 3 and installed the corresponding XenCenter. The "Migrate to Server" menu item is no longer present when right-clicking on VMs or under the top-level VM menu, for my 6.5 pool. It is present in both places for my Dundee Beta 3 pool. Removing Dundee's XenCenter and installing 6.5's restores the menu item. Updating to Dundee's XenCenter removes them again, leaving me forced to migrate VMs in my 6.5 pool from the command line (which works fine).