SSL post to IIS hangs.

I am trying to do a post using SSL from my NT4.0 box
to IIS4.0 web-server. I have set HTSSLhttps_init(NO).
SSL read always hangs at
GetMessage(&msg,0,0,0)in file HTEvtLst.c

I added following lines at the beginning of function
HTSSLReader_read() in file HTSSLReader.c

#if defined(_WINDOWS)
  Sleep(1); /* Sleep for 1 millisecond */
#endif

Now Post works fine.
Does anyone know why my post was hanging and why it works
when I add Sleep() to the code.

Thanks,

-Chandra