This is really easy to reproduce:
1. Run the latest Alfresco 3.4 HEAD or 4.0 with CIFS enabled.
2. Mount CIFS in Mac OS X Lion.
3. Open a large Word file from a local Mac directory, say your Desktop (make sure the document is at least 4 MB), save it (File -> Save As) to a directory in the repository via CIFS, say User Home.
Expected result: Document saved successfully into the Alfresco repository.
Actual result: It failed with one of the two error messages below (also attached as screenshots).
Message 1. The disk is full trying to write to Alfresco. Free some space on this drive, or save the document on another disk.
Message 2. There is an unrecoverable disk error on file Word Work File D_1.tmp. The disk you're working on has a media problem that prevents Word from using it.