FYI, read http://secunia.com/advisories/46512/. If possible, please repackage soapUI with the latest JRE, 6u31, where this issue has been fixed, or provide a patch. I solved this problem manually by switching the JDK to the latest and it all works fine.
soapUI version: 4.0.1
JRE version: pre-packaged JRE with soapUI 4.0.1
platform: Windows 7