2nd MC-16C for ubr7223 = telco-return probs ??

[Psychosis]

We have ran a single, 6 upstream port mc-16c cable modem card from day one.
We have a mixture of telco-return and 2way modems on the system. We are
currently setting more nodes up for 2way modems. We have 7 nodes set up now
for 2way and only 6 ports. We purchased a 2nd MC-16C to go in our UBR7223
for 6 more ports. Problem is our telco-return modems dont like the cable
bundle 1 master that i have to put on the 1st cards interface. Has anyone
on the list been through this experience before and if so is there a way to
make it work with the telco-return modems too?

I can paste the running config of the ubr if needed.

Thanks