Tested on various HW and OS (Win64, Linux64)
Latest tested version: blender-2.70-c17acf1-win64 (official daily build)
Broken: somewhere in 2.70
Worked: (optional) 2.69
Short description of error
In some cases boolean modifier (difference) causes Blender to freeze (infinite loop type, full load on one CPU core).
In test blend file is also used Solidify modifier, however booleans freeze even if Solidify is applied with thickness value near freeze case and manipulating objects by grab and rotate.
Exact steps for others to reproduce the error
Open attached file, and either run animation (alt-A) or set Solidify modifier thickness on cube.001 to >1.7.