Invalid web query Excel 2007
 

I am running Vista , IE8, and Excel 2007 (all fully updated). Yesterday I
ran around 50 web queries and they all worked correctly pulling data from
finance.yahoo.com, today all web queries return with the message "invalid web
query" There were no system updates overnight.

I cleared the IE8 cache (a reported solution), but it did not resolve the
problem.

I then copied the files to another machine - running XP, Firefox, and Excel
2003. Excel recognized the 2007 file formats, converted the data, then ran
all web queries successfully. This seems to indicate that the web queries
are not invalid.

Any idea on how to resolve the issue?