signal 10 in malloc call???

[Juergen Wagner]

The most likely source of strange effects like the ones you describe are
some strcpy/strcat/scanf/fgets/... which write beyond the end of some string
of chars. 

However, this does not necessarily have to be the cause of your problems.
Consider also the following:

o  functions using up more arguments than provided,
o  functions called with a variable number of args but popping them
   with the wrong size.
o  scanf/sscanf reads double into floats.
o  some buffer isn't large enough.

All this might not clobber the malloc area but the call stack, in which case
you may detect that much later, and in an unexpected manner. Some time ago,
somebody posted a malloc package with debugging aids, and I'll be glad to 
forward it to you.

-- 
Juergen "Gandalf" Wagner,		   gandalf at csli.stanford.edu
Center for the Study of Language and Information (CSLI), Stanford CA