Script error when running Fixupdate.vbs

When trying to run the FixIssues.exe on a Win2003 AD DC the completed message came up too quickly. I ran fixupdate.vbs instead from a command line and the script encounters an error details:

Number = 424

Description = Object required

Failed to open:./2012-11-26_14-41-37_#server#_000-Output.txt

C:\Temp\Fixupdate.vbs(740, 5) Microsoft VBScript runtime error: Object required: 'file'

It looks like it is failing to create any output files and so when it looks to open it to begin logging, the file doesn't exist. 

I can't  see what the problem would be as I'm logged on and I am a domain admin. I have run this on a similar DC and it worked without issue.

Any other ideas?

Thanks,

Martin