SOAP UI test failures in 5.6.0

Hello SmartBear Team,

We have a forked repo from SOAP UI and are upgrading the same from 4.5.1 to 5.6.0 to address CVE-2014-1202 vulnerability.
But are stuck with test failures with the following exception on Jenkins build ( with xvfb plugin and X servers ) .

Exception in thread "main" java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which requires it.

We bumped into this question on the community with the same error in test failures.
As according to the response by SmartBear Support 

"Unfortunately we only have workarounds for this, if you have X component you can specify: "export DISPLAY=:0.0" before starting application and this should also work. We currently have a defect logged in our defect tracker with SOAP-2705 reference number."

We tried the workaround mentioned - but did not help us.
Could we know if the specific defect was already addressed ( couldn't find this fixed from SOAP UI release notes ) or if not please do let us know any other workaround we can apply as a patch?

Thank you