Mesh dropping IGMP reports after 1 hop

[otherJeff]

I am running 7 x HP5400 switches located across 3 onsite locations connected together by a 10gig mesh as my core network. I recently found the need to enable PIM on my internal network routers to route multicast traffic from my CCTV VLAN onto the default VLAN where the CCTV clients were to be located. These routers connect directly into 2 of these core switches in different locations and are set up in high availability using VRRP.
What is happening is that some of the CCTV clients will connect to the multicast video streams and then drop the streams after about 4min 30 secs while other client connections do not drop the video streams. The issue is that IGMP reports are being dropped after the first mesh hop and not making it back to the router querier causing the flow to be pruned. In every case I have been able to correct the dropout issue or cause a working client to begin the dropout cycle by either moving a client to within 1 mesh hop or moving the client away to > 1 mesh hop. This is across all clients and all switches and both routers ie. a master router forced failover would in some cases change the mesh hops and the clients ability to maintain the video connection.
So, I am running K.15.09.0012 switch sofware with BOOTROM K.15.28 which is not the latest, does anyone know whether this problem has been addressed in later revisions or whether there is some CLI mesh command to resolve this issue? An upgrade of the entire mesh is disruptive given my workplace is a 24/7 operation and does not appreciate outages, however, I will wear the pain if there is a fix.

[Vince-Whirlwind]

I distinctly remember encountering an issue on my 5400s with something having default hop-count of 1, but I can't remember if it was multicast.

I just read the 5400 Multicast Routing manual and it says the default is "0" (ie, it doesn't check).

 The command is ip pim-dense ttl-threshold ...

[otherJeff]

Thanks for your reply Vince, however, I am not running any IP routing on any of the 5400 switches. I don't believe it was supported in conjunction with meshing in the K.15.09 version of software. I am only running IGMP on the 5400 switches and PIM is running on my routers.