Sorry, guess I wasn't clear. That is what I'm doing. My code calls IO::Socket::accept, but in debugging I tracked it into that function, to the call to perl's accept(). That's the code I showed, my hacked version of IO::Socket. IO::Socket::accept's call to perlfunc's accept blows up.
Oh, sorry for the misunderstanding ...
Are you passing a timeout to the IO::Socket constructor?
Also, are you forking after the creation of $sock? if so, all the child processes call accept() upon $sock?
A .t file that triggers the "bug" would be more than welcome.