Help!

My computer I was using MPLAB on crashed* while I was using MPLAB.  The
result of which
I cannot trace a program at source level now when using the simulator,
everything else seems
fine.  Whenever I do a RESET and single step MPLAB brings up the Program
Memory Window
for single stepping etc.  The option in the "Environment Setup" (Ctrl+F7)
for tracking source
code is checked.

Has anyone else had and overcome this problem?  Anyone know of a setting to
re-enable source
level tracing, changing an INI file setting...?

Any help would be much appreciated.

TIA
Maurice

*Actually the laptop battery went flat!