Stopping Contact person replication to R/3

Hi,

In CRM order, we  have a contact person, but the corresponding contact person mapping in R/3 (CRMPARNR) got deleted for a particular sales area.

So we are getting an error message Partner with Partner role AP cannot be converted.

Now, how can we stop the replication of contact person to R/3 for this sales area only?

I have checked the function module in CRMC_BUT_CALL_FU.  But this is not getting triggered when i try to edit the order and save and click  distribute it to R/3.

Thanks & Regards

Sunil