Yeah, I kind of figured it was an issue with fork being emulated with threads, but I was thrown off and confused by the fact that it worked fine as long as the connections were all concurrent and the fact that the problem didn't arise if sockets weren't involved.

As it turns out, you were correct. The issue was some sort of interaction between sockets and the fork emulation that aggrivated the bug in the regexp engine mentioned explicitly in perldoc perlfork (not sure why I didn't think to check there originally). Upgrading to 5.8.1 fixed it completely (both issues, actually).

Thanks!

bbfu
Black flowers blossom
Fearless on my breath