Bad filenumber Error / warning messages in cygwin shell

[zaphodb]

Hi

I'm running a trial version of the commercial X-server Xwin32 (version 5.11)
on a W98 platform and I'm using the libforms89 library to run a X-window
application from a cygwin shell. This works fine for me but
while this application is running in the shell window I get loads and loads
repetitions of a specific message:

In select [asyn_io.c 170] Bad file number--Bad file number

This alone seems to consume quite a bit of processing power.
Does anybody know what is causing this and how this can be helped?
Is this a libforms or cygwin or Xwin32 problem?

T.i.a.

Zaphod B.