Photoshop :: Network Files - Error Messages - Using Compatibility?

I use a Windows 7 64 bit Dell at home and at work. Both have Photoshop CS6 (not extended). This week when I saved files at home using file compatiblity (since co-workers in my office are on CS 5.1) and FTPed them from home to the work network I ran into all sorts of issues.
 
5.1 users reported getting all sorts of errors including...The document contains unknown data which will be discarded to keep layers editable... and another one about missing "color books" 

I read about cross version problems with shapes with the new CS6 vector strokes applied. Sure enough, when I sent CS 5.1 co-workers small test files by email they could open all of them but the one with the shape with CS6 vector stroke. So I went back to the larger PSDs and removed the strokes from any shapes, but the office still could not open the files.
 
I too, even though on the same CS6 product get an error "There was a problem reading the layer data. Read the composite data instead?" If I click to do so I get another error "Could not complete your request because the file is not compatible with this version of Photoshop" which is simply not true wince both are CS6