I once again tried to upgrade to the latest apache (now 1.3.29.0.1-5) and still found this behavior. However, I managed to discover that the thing that was hanging the apache processes was actually logrotate stuck in a write() call that never returns. This behavior never happened with apache 1.3.28 and I have the most recent logrotate installed. Configuring apache to not use logrotate and to log itself caused this behavior to stop.
I still consider this a bug in apache but have no further specifics to offer at this time.
