Out of curiosity - what's the background here?
Some switches need to be configured regarding IGMP Snooping and - in some cases - IGMP versions need to be uniformally configured on OS's. I.e. it doesn't help you if your switches use IGMP v2 but your client OS's use IGMP v3.
It would be the first time I hear about someone needing to buz a "premium" license to just be able to use multicast. Make sure first that it's not a configuration issue first of all.
LANDesk EMEA Technical Lead