Operating System: Windows 7 x64

Graphics cards tested: HD4000, HD3000 and GTX 580m

Blender version with error: 2.67RC also tried 2.66-r56493-mingw64

Version that works: 2.66a

Issue:
Noticed the improved Bevel modifier (while a great improvement used on its own), produces unusual results combined with a Boolean modifier in recent versions of Blender.

Attached .blend file contains the default cube with an added sphere, the cube has a Boolean modifier (Object: is the sphere) Operation: set to 'Difference'. Bevel modifier added last. Opening this file in Blender 2.67RC highlights the issue with all old .blend files containing Boolean and Bevel modifiers.

This is further exasperated, opening the attached file (saved form Blender 2.67RC) in Blender 2.66a, shows backwards compatibility issues, requiring replacement of all Bevel modifiers. After Bevel modifier replacement, files are fixed, until those files are opened in a recent version of Blender, upon which corruption is once again evident.

The higher the Segment setting saved (in Blender 2.67RC) the greater the corruption upon opening that file in Blender 2.66a