SquareSteelBar, up to v0.5.3 (current public release) S3D is not very stable with SH3 (modded/patched/stock). By the end of the week I will release v0.5.4 which is made fully compatible with SH3 (apart from some issues with GWX, but I contacted their technical crew)
Please check my
online changelog for improvements in upcoming release.