I have a problem with Word 2010, when I create a new blank document and attempt to save it as a .docx file I receive the error:

"Cannot save the files. 'test.docx' is not a valid short file name (maximum eight characters, plus a three-character file extension). Type a valid file name, and then save the file again."

We do have Office configured to use .doc files as the default format, which does seem to be part of the key. If I convert it first and then save it I have no problems. It also seems to be a problem with particular image builds as some other builds don't suffer.

Does anyone have any ideas as to what we do to fix this?