Another(?) ADVAN5 Problem

This note is addressed to all nonmem users using a VAX/VMS system (our version is 5.5-2). The problem we are facing is that when we run a simple 2 compartment model using advan5 the program ends even before the iteration process is invoked (the VAX gives a divide by zero error message in the DDDFRS routine line 23). Yet the same code and data set run successfully on a SUN system. If any users have some suggestions as to what we can try we would be most appreciative. (Interestingly a one compartment model runs without any problem)