Something blocking in libpq_gettext?

Often, when we get short-lived network problems (like when our network
admins break the firewall), postgres client apps will lock-up. They do
not recover once the network is back to normal, do not time-out, and do
not fail with any sort of error.

This has been happening since at least postgres 7.4.7. We are currently
running 8.0.3 (now upgrading to 8.0.8).

As near as we can tell, it looks like libpq blocked inside poll inside
libpq_gettext.

#0 0xffffe405 in __kernel_vsyscall ()
#1 0x005a31d4 in poll () from /lib/tls/libc.so.6
#2 0xf7fd71ff in libpq_gettext () from /usr/lib/libpq.so.3
#3 0xf7fd7331 in pqWaitTimed () from /usr/lib/libpq.so.3
#4 0xf7fd73a1 in pqWait () from /usr/lib/libpq.so.3
#5 0xf7fd53fb in PQgetResult () from /usr/lib/libpq.so.3
#6 0xf7fd5524 in PQgetResult () from /usr/lib/libpq.so.3
#7 0x081b43b3 in SQLInterface::execute (this=0xf7ce3080,
cmd=0xf7ce0074 "execute lock_games ( '100' )") at SQLInterface.cpp:138

Can anyone offer any solutions, suggestions, fixes? We cannot reproduce
this at will, but are willing to provide more information when next it
occurs.
__
Marc