pdhcp.ini and multicasting

I want to make sure I have this right before I drive my LAN guy up a
wall.

I can multicast from the same subnet, but not through the router
(HP Procurve 9300) (We're using NW6.5 Zen7sp1)
I can unicast through the router
The client will pxe boot across the router, but stops at the Waiting
for multicast session to start.
The multicast server shows 0/1 client (The multicast session is
configured to connect at one client)

Do I need to configure anything else on the Novell side?
like, for example, the mtftp parameters in pdhcp.ini?

Kirk
Dawson COllege, Montreal