As already announced I worked on fixing bugs and problems that users (mostly the users over at the newton boards, so kudos to them) discovered in release 1.5 of the NewtonPlayGround. Sadly there were more bugs and problems than I suspected, but none of them was very serious.
So I now (hopefully) present you release 1.51 of the NewtonPlayGround, which can be obtained here. It also includes a new feature, namely dampers, for slider and hinge joints. This allows you to e.g. create complex suspensions like the one below (which is included in the download of 1.51).