Version Mismatch Fault!!

I tried to invoke a java class based web-service in a bpel process using invoke activity and got the following fault:
Version Mismatch.
After digging into it for a while, i did not get any clue. Finally, i resorted to google and found the following:
My web-service used couple of bindings: SOAP and SOAP1.2 And accordingly it had two ports. Now BPEL PM somehow finds this as a conflict, do not really understand why.
As a workaround, I removed one of the ports and binginds and to my surprize, it started working well.
Remove either of the bindings and ports and it will work.
I've tested this on SOA Suite version 10.1.3.1.0. And this holds true for 10.1.3.3 also.