Desktop Manager, Virtue, mach_inject and 10.4.4+ intel
I had trouble since yesterday with Desktop Manager and Virtue. And then I found this page, which reports that
"Important restriction: In 10.4.4 (intel build), Apple removed the ability to send low-level mach commands from one task to another. A task trying to control another one must now be root or belong to the procmod group. If you want to allow mach_inject to work again for your account, you need to add yourself to the procmod group. Another option is to enable it to work for all accounts on the system, by changing the security policy for task_for_pid(). Please understand that both options re-open what some consider as a security risk."
and goes on with detailed instructions.
I went ahead and implemented both of the proposed solutions, then rebooted. Virtue launched on login, and is now working (as far as sticky windows and moving windows between desktop, which was broken before I followed these instructions).