Autofs: Ambiguous or Unknown Option

[pgb205]

Get the following when I try to start autofs daemon

sudo /etc/init.d/autofs start
* Starting automounter ...
/mnt/auto/usr/sbin/automount: Ambiguous or unknown options
* Failure on /mnt/auto

My config file looks like:
auto.master
/mnt/auto /etc/autofs/auto.auto --timeout=5 --ghost

auto.auto
cdrom -fstype=iso9660,ro :/dev/cdrom

/var/log/messages is only showing my trying to start up the autofs but not cause for failure.
I'm running the latest gentoo kernel 2.6.30-gentoo-r5 but the problem was the same with the
last few kernels as well. Autofs is selected to be compiled in the kernel.
I'm out of ideas on how to troubleshoot this further so any help would be appreciated.

thanks