Have you raised a CA Support ticket?
I've experienced multi-cast issues, in particular, modifications to processes, where the 'cached' process on one VM server retained the old version of the process.
You don't indicate what you are 'xogging' in. I have never experienced multicast issues using xog, with the exception of the above where the process was migrated from TEST to PROD using XOG, but the above was not an xog problem, as I was able to demonstrate to CA Support that even updating the process via the Admin UI, it was still failing.