autofs automount expiration / remount is causing mountpoints to hang in RHEL5

Issue

• There is an automount bug running kernel-2.6.18-194.el5 and autofs-5.0.1-0.rc2.143.el5. The logs show that mkdir invoked automount to mount an NFS mountpoint and remains stuck with autofs4_wait in it's wait channel. Follow-on processes also trying to use the mount point end up in a D state.