I would like to report a bug, which I encountered in TBNL 0.8.2. I've been meaning to work up a patch, but I haven't had the time yet. I don't even have the time to check if the bug is present in 0.8.8. :/ So, please forgive me for merely reporting what I saw, for now.
I'm using SBCL 0.9.6, but I suspect that the bug isn't a grotty implementation-specific issue.
Basically, when you return the empty string as a response, after about 250 responses, you run out of file handles and everything stops working. To get around it, you can return a string with something in it, or you can do something wonderful like this, around line 123 in modlisp.lisp:
(when (or t (plusp content-length)) ;xxx timjr
Cheers, Tim