Error Code: U44M1P7

I am getting  Error Code: U44M1P7 while installing Illustrator 16.0.3, updating from 16.0.0. I have tried downloading it manually and installing a get the same message. I have also tried installing the intermediate patch 16.0.1 before 16.0.3 but get the error message for both. All other Adobe software has updated OK.

The log can be sent if necessary (can't find where to attach it here). Peter