I think this is not a bug but time scale is not compatible with the environment. Play and try fire sond in gravity field with low tempo and hight tempo.
Explosive behaves differently. I use in event sheet- When explosives overlapping blue grav field of planet > apply impulse 0.001 towards his planet. So simple physics action changes in other timescale
dl.dropbox.com/u/44710358/W%20stron%C4%99%20s%C5%82o%C5%84ca/index.html
For example when explosive overlapping Jupiters grav field in 8x tempo(0.8 timescale) explosive cant escape but when i switch tempo to 2x explosive quietly passes through a field of gravity