Further investigation (Google) revealed that it is a macro inside Office 2007 that is causing the problem. Exactly why, I don't know. But here is my work around, use at your own risk ;-).
Make a backup of the file and edit the file in "C:\Program Files\Microsoft Office\Office12\1033\EXPTOOWS.XLA" (with Excel):
1. Open the file with Excel
3. Locate the following code:
aTarget(iPublishDesc) = Title
lVer = Application.SharePointVersion(URL)
4. Insert right after: lVer = Application.SharePointVersion(URL)
the following line: lVer = 3
5. Save the file EXPTOOWS.XLA
Make sure you overwrite the file.
That's it! Anyone welcome to leave a comment as to why this happens, or what the consequences would be if you edit the EXPTOOWS.XLA file.