But without physics the direction of the speed gets calculated correctly. Actually we worked this angle-problem out (or not ?):

(Quote EvilSOB http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=257365&page=2)
vec_diff ignores the switching between 0...360 or -180...180 of the angles, when these values are being stored in a manually created VECTOR, they wont be treated as angles, and therefore wont suffer the +180, -180 clipping.

Maybe that's not he whole story ?