Unlikely unlikely, but ...: Any ideal components with inductive reactance? Long ago I saw simulations go inexplicably insane due to this. Perhaps due to divide by zero's / infinities. Similar to inexplicable behaviours when you inject current via microcontroller body diodes :-) Russell > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .