We used Analog Workbench on Sun UNIX workstations for many years here at work, but transitioned to a Windows-based SPICE package about 8 years ago. The package has worked reasonably well, and we have gotten great technical support from the vendor. However, we are facing some especially vexing convergence issues with some circuits that we are re-simulating (they worked fine on Analog Workbench many years ago), and I was looking for input from other power-SPICE users out there about SPICE packages that you use and have found relatively free of convergence issues (especially DC convergence). Or, if you have run into convergence issues, and your SPICE package has enough hooks and handles to help you to get the simulation to converge and start. Thanks for any input. I'm not mentioning which package we're using because of the good technical support we have gotten over the years -- they just haven't been able to help with this particular circuit's convergence problem.