[Dovecot] error in config file?

[Robert S. Jagger]

When I start dovecot I am getting an error about the ocnfig file. 

watson:~# /etc/init.d/dovecot start
Starting mail server: dovecotFatal: Error in configuration file
/etc/dovecot.conf line 185: Missing value

So I look int /etc/dovecot.conf and line 185 is

mbox:~/mail/:INBOX=/var/mail/%u/

Which seems like valid syntax according to the docs.
I am using dovecot 0.99.10-2