reaping fd's and flushing buffers

Sure enough, after I say that all my fd reaping issues are solved at the Haskell level, I've been bitten by issues that look like the RTS doing things behind my back wrt. reaping fd's etc. etc. Basically, while I used socketToHandle the fd's got closed prematurely, and once I eliminated all uses of it, the socket fd's appeared to leak despite attempts to explicitly close them. Also, there were some very strange goings-on with respect to attempts to flush buffers after the fd's they were being flushed to were closed. So, what are the semantics here? Bill