Spectre Convergence problem (Dynamic Comparator)

Hey

I am trying to simulate Dynamic Comparator in Spectre but facing
problems with convergence. Right now I am simulating schematic level
and its completely balanced. For certain input reference with fixed
input (which is close to the ref. level), the output decision changes
from one clock pd. to another (not always in consecutive pds.). I tried
playing around with the tolerance limits but that is not helping me.
Can anyone suggest something?

katyal
consecutive