**System Information**
Windows 7, Windows XP
**Blender Version**
Broken: 2.75a
Worked: probably never
**Short description of error**
Shape key data in a bmesh contains incorrect values.
Also, simply iterating over the data items causes a crash on Windows (EXCEPTION_ACCESS_VIOLATION). Couldn't reproduce the crash on Linux.
**Exact steps for others to reproduce the error**
Run the script in the attached .blend file.