We have experienced the same sort of symptoms both transferring calls from our attendant console (Nortel's PC CONSOLE) to a CDN controled by Genesys, as well any calls which first interact with our CALL PILOT environment for a menu option before being transferred to Genesys for Routing.
What we found is that the calls coming through the PC CONSOLE or CALL PILOT were not always releasing their control of the call before Genesys would try to route the call. Most of the problem calls from CALL PILOT were found to be calls that were being attributed still as "Consult" calls rather then "inbound" calls, because of the fact that the Nortel still had not released the call properly even though it had already arrived on the CND. The result would be that these calls would drop through to our underlying ACD queue because Genesys was not able instruct the switch on what to do with the call before it was too late. We were actually able to find examples of calls that did get routed correctly of the Call Type actually changing from "Consult" to "Inbound" if we delayed the Genesys routing until the Call Type changed so it was no longer a "Consult" Call.
So the was we have things set up currently is that we actually send our calls initially to a preliminary CDN which only checks the CALL TYPE before transferring the call the primary CDN which will route the call to the appropriate skills set. If the Call Type is a "Consult" call we hold the call for 1 second and then check again to see if the call type has changes to "Inbound". At the same time we have also configured this preliminary CDN to use the Primary CDN as it's default, rather then an ACD queue. The result being is that any call which might get dropped, even if we do delay the call, will still get transferred by the switch to the Primary CDN. The result being that we no longer get reports of calls being dropped from either the PC CONSOLE or CALL PILOT.
Our next idea will be to not even try and route the call from the Preliminary CDN, but rather to just unload the strategy which pauses the cal on this preliminary CDN and just let that switch transfer the call to it's default DN (which is set as the primary CDN we want the call to go to anyway). That way we think that the Nortel switch itself might complete a clean transfer from the PC CONSOLE to the Primary CDN (through the preliminary CDN's default) without the PC CONSOLE still having control of the call when Genesys tries to route the call itself. To date however I have not tried this, as things seem to be working the way we have them, it's just a little messy right now as I need to maintain twice as many routing scripts and CDNs.
In the case of your customerfs environment, is the ACD Queue that the call arrives at set in the switch as the default DN of the CDN? If this is the case I suspect that your problem may be similar to our issue. You may want to try and delay the call to in some way (such as what we have done) to allow the attendant console time to release control of the call.