Environment
Red Hat Enterprise Linux(RHEL) 6.3 autofs-5.0.5-54.el6.x86_64
This leads me to believe that upstream is aware of this issue and someone there is working on a fix.
I was reading your posts with Joerg Schillings comments on Linux NFS (in the zfs/xfs/jfs thread) still in the back of my head, for some reason ;)
The changelog entries in upstream's autofs rpm go back thirteen years. One would expect some measure of maturity and stability here, yet autofs is a frequent source of problems. I remember another major problem we ran into somewhere around CentOS 5.2 or 5.3.