Attached are the outputs from Valgrind and GDB that I
believe shows another problem with the multi-socket API.

While it is certainly possible that it is a bug in my program,
it sure looks like multi_runsingle() is referencing a previously
free'd connection (full of 0x13's).

I can post the program that reproduces the problem if that would
help ( it's only around 700 lines ) but it takes a few minutes
set it up, it's basically a local proxy server that sits between
Firefox and the internet.

I will try to dig around a little more to see if I can find
the cause, unless this attachment makes any light bulbs flash
on your side.

 - Jeff