OSD - Multicast not working properly

I have multicast up and running on my test environment and found that it doesn't seem to work through Software Center. If I PXE boot the machine and run the task sequence, it will join/create a multicast session like it is supposed to and everything works perfectly. If I start the multicast session through Software Center or as a required deployment (so skipping PXE booting), it just starts downloading the WIM, it won't create/join a multicast session.  
 
Is this how it is supposed to work or am I missing something? I'm going to be trying autocast later today (so disable the schedule) to see if it works any better but I thought I'd check here to see if anyone encountered and fixed this problem.