You curse you swear but then you read this:
http://patrikluca.blogspot.com/2009/01/invalid-look-up-value-durig-upload-of.html
and fantastic its' all fixed and into the bargain you have discovered something new in office 2007 called the document inspector.
And wait a mo' what if you need to do remove 'hidden metadata' from your Office 2003 documents - well those nice people at Microsoft have an add-on for this very problem:
http://www.microsoft.com/downloads/details.aspx?familyid=144e54ed-d43e-42ca-bc7b-5446d34e5360&displaylang=en
