Looks like I finally solved that
spinning-crates-on-the-ground problem, along with other serious bugs. Added possibilty to serialize the whole bullet world into file, that can be loaded from external file, VERY crucial for debugging that rotation bugs. New version is downloadable from github, linux binary and zip file will be provided at the weekend. I'm going to be away for a few days so I'll do this stuff when I come back.
I also stumbled upon nice bug in bullet's btScalar.h:
Code:
#define SIMD_PI btScalar(3.1415926535897932384626433832795029)
#define SIMD_2_PI btScalar(2.0) * SIMD_PI
...
#define SIMD_DEGS_PER_RAD (btScalar(360.0) / SIMD_2_PI)
Can you see it? This has been fixed after SEVEN years of bullet2 development, in revision 2717! But the zip file is r2704, so I encourted it.
(hint: missing parentheses and operator precedence)