When I attempt to check the "Report Unconstrained Paths" box during an analysis against timing constraints (in the GUI), TRCE runs for a few moments, then crashes and reports a Dr. Watson error.
To work around this problem, add a MAXDELAY constraint to the PCF, as in the following example:
timegrp "rams" = RAMS (*) ;
TS01 = maxdelay from comp "Clk" to timegrp "rams" 20.0 nS;
Please note that this is a coarse constraint, and it will remove all paths from the above OFFSET IN constraint.
This problem was fixed in the 4.1i software.