This sounds like a pretty straight forward integration problem. We're probably not getting the expected packet information from the switch on the forwarded call which could be for any number of reasons.
A tech support person will want to open up the Integration Monitor and look at what we're getting from the switch to determine how to go about solving your problem. That may be altering your integration definition file, adjusting DTMF delays, pausing longer to get information from the switch, having you adjust the programming on your switch etc...
It's impossible to speculate what's happening without getting that information first. Unity has some good diagnostic tools in there for tracking this type of stuff down. Give our support folks a ring, they can help you out.
Jeff Lindborg
jlindborg@activevoice.com
http://members.home.net/jlindborg