SAP Adapter Problem sending IDOC to IS

We have been having intermittant problems sending IDOCs from SAP to the IS. Normally everything works fine then we’ll get the error “ISR053 RFCabort: Transaction processing rejected, retry later” when viewing SM58. It’s difficult to correct but it seems that stopping the listener and restarting it does have some positive results but not always.

I believe it may be due to a high volume of transactions and the interface getting bogged down but I have not been able to find anything to help resolve the issue. We currently run the 4.0 SAP adapter and are in the process of installing the 4.6 adapter to see if this will resolve the problem.

Any suggestions?