SAP Business Connector!!!

I have SAP Business Connector v 4.6 that connects to many partiners one of them is using BC whith Guaranteed Delivery. The SAP BC Server is configured to use Secure Sockets Layer (SSL) to
provide secure communications with the server. it seems each time i send or receive IDoc to that partener it changes the values of the feilds under Secure Proxy to “null”. and each time this happen i have to remove the null by editing the fields and save them empty.
Any Suggestion to solve this problem