Vista - Windows Automatic Update crash

Hi,
Recently after activating my copy of Home Premium x64 a dialog box has been popping up saying that the automatic updates has stopped working. If I press close the program the dialog box comes back about half a minute later. The details of the crash are:

Problem signature:
Problem Event Name: APPCRASH
Application Name: wuauclt.exe
Application Version: 7.0.6001.18000
Application Timestamp: 4791a227
Fault Module Name: StackHash_2ea1
Fault Module Version: 0.0.0.0
Fault Module Timestamp: 00000000
Exception Code: c0000005
Exception Offset: 000000100000002d
OS Version: 6.0.6001.2.1.0.768.3
Locale ID: 2057
Additional Information 1: 2ea1
Additional Information 2: 0411f401154786662c220fbfdaf8b4f5
Additional Information 3: 16ba
Additional Information 4: 954b39dd611850a61426512ac5220bbc


I had to also change the date to get the activation to work as the computer was a few months behind. Is there anything I can do?
Thanks

Anyone?