WS-Security Signature not working via SoapUI

I've got a working solution for WS-Security via CXF, using the Signature
action on the WSS4J interceptor. My current code base is:
https://github.com/garethahealy/jboss-fuse-examples (directories with
ws-security-https-cxf*)

So the problem i have is that i can make a call from the java client
(included on github), but when i try SoapUI (project included on github
under client directory), i get "The signature or decryption was invalid"

From a quick debug, its failing on this line:
http://grepcode.com/file/repo1.maven.org/maven2/org.apache.ws.security/wss4j/1.6.14/org/apache/ws/security/processor/SignatureProcessor.java?av=f#420

Now the question is. What am i doing wrong in SoapUI? I think i've setup
everything, but i must be missing something since i cannot get it to work.

Any help is appreciated.