Unable to JB due to crash

I've updated to 5.0.1 and am trying to JB my ip4. However when following the instructions to JB it gets to uploading the first stage of the JB and then crashes (Win XP). I've tried versions 0.9.10b1 /b2 /b3. After it crashes I have to restore the phone before I can try again - very time consuming.

Has anyone came across this issue and have any ideas how to fix it?

 

Yes I'm running it as administrator.

I have tried another half dozen times, on 1 occasion using 0.9.10b1 it managed to get to the option of installing cydia, this time it did not crash but just hung there for over an hour before I gave up on it.