[PD] how to debug a PD patch

[plutek infinity]

greetings!

the question:

is there a way to make pd tell me specifically what part of a patch is 
causing a crash, so i can identify the problem and fix it? the debug 
command-line option doesn't seem to give useful results for my current 
issue.

background:

i have a patch which is significantly complicated, including many 
subpatches, etc... it used to run just fine, but has recently started 
crashing when i click on some toggles in my interface. however, it's not 
always the same toggle that causes the crash, nor is it a reliable 
number or group of toggles, as far as i can tell.

there was one message which was supposed to be received by a toggle, 
but which wasn't being received the last time i opened the patch. i 
fixed that error, and saved the patch. however, the crashing was 
happening both before and after that fix, so i'm afraid some other 
little things in the coding may have changed somehow. don't know how 
that could have happened, but anyways....

many thanks in advance... cheers!
.pltk.