I agree with Ken. You're talking about tolerances, and timestep control parameters for the digital solver, which don't exist (because they don't need to exist - it's not doing adaptive timestep placement using tolerance controls in the simulator).
If you can't reveal all your models here (for whatever reason), please contact Cadence customer support (
http://support.cadence.com). I doubt very much whether this is a tool issue - most likely it's a modelling or test bench issue, as Ken suggested, even if you're not using any of the connect modules to do this. We (Cadence) would be happy to help pinpoint any model or setup problem you might have - and if it really is a tool bug, we can fix it. The first step is to see what the actual problem is though.
Regards,
Andrew.