I am using Synapse 1.1.
ah.. the culprit! This issue was fixed for 1.1.1 as per Synapse-220
Do you think moving to Synapse 1.1.1 solves this issue? As the software is in QA, I do not want to
upgrade the version.
This is your call.. 1.1.1 obviously has new features and bug fixes over 1.1, but if all that you require works on 1.1 and you are satisfied and has [almost] completed QA ..
 Is there any way I can make this work in Synapse 1.1?
Yes, through a binary "patch" which you can place in your lib/patches directory that will fix this issue. We are also working on getting Synapse 1.2 out within May, with the pending Axis2 1.4 release and its associated packages.

Let me know if you want to move to 1.1.1, wait for 1.2 or would like a patch for 1.1..