emacs hanging occasionally after tramp/scp invocation

[Marc Girod]

Hello,

I am running tramp 2.2.3-24.1 over GNU emacs 24.2.1 on Cygwin.
I connect to a GNU linux 2.6.32.59-0.7 x86_64 host.
My local ssh client is:
OpenSSH_6.1p1, OpenSSL 1.0.1e 11 Feb 2013

The remote ssh is:
Remote protocol version 2.0, remote software version OpenSSH_5.2

The connection is between Ireland and Sweden, so there is a
significant latency (46ms).

Occasionally (maybe once a month), my emacs will hang.
I am left on Cygwin with a suspicious entry in the ps output:

     7280    6528    7280       7652  ?       654351 11:28:09
/usr/bin/chown <defunct>

6528 is /usr/bin/emacs-X11

What should I suspect?
Could there be a missing waitpid?
There may be an error condition on the remote side (automounter,
firewall, ...), but shouldn't the client survive it?

Thanks,
Marc