RFC failure in SAP Adater 6.5 after SAP upgrade to ecc6

In our integration environment, SAP was upgrade to ECC 6.0 from 4.7. We were using SAP Adapter 6.5 in IS 7.1.2 After this upgrade, users were complaining that they were seeing a delay in messages/Idocs sent from ECC 6.0 to webMethods, when they monitor at MWS.

Idoc created at 2:00 CET in SAP, is reaching wM SAP Adapter at 2:30 CET. Even during peak load, we see it took arnd 2 hrs for the Idoc created in SAP to reach wM SAP Adapter

When we look into trace files, we can see the below errors were occuring oftenly in the trace file:

**** ERROR file opened at 20100308 101850 W. Europe Stand, SAP-REL 640,0,165 RFC-VER 3 881549 MT-SL
T:16028 Error in program ‘PYARAWMR3’: <* RfcDispatch [27] : returns 1:RFC_FAILURE

**** ERROR file opened at 20100308 103239 W. Europe Stand, SAP-REL 640,0,165 RFC-VER 3 881549 MT-SL
T:16028 Error in program ‘PYARAWMR3’: <* RfcDispatch [18] : returns 1:RFC_FAILURE

**** ERROR file opened at 20100308 115002 W. Europe Stand, SAP-REL 640,0,165 RFC-VER 3 881549 MT-SL
T:16028 Error in program ‘PYARAWMR3’: <* RfcDispatch [10] : returns 1:RFC_FAILURE

‘PYARAWMR3’ is the RFC destination/Program Id provided by SAP and same has been used in configuring Outbound SAP listeners too.

When BASIS team trys to test the connectivity of this RFC with wM, they see its taking more time. And as well they see lot of records with message “Error opening an RFC”.