I think there was a Thunderbird bug related to showing subfolders. It was talked about here just a few (3-7?) days ago..
On Wed, 2010-07-07 at 12:28 -0400, A. J. Giurato wrote: > I've completely closed and reopened Thunderbird many times, and I've hit > refresh too. Dovecot has been restarted multiple times. Squirrelmail has > been logged out and back in. Apache server serving squirrelmail has been > rebooted. > > +--------------------+ > | A. J. Giurato | > | a...@pastalovers.net | > | (678) 516-3710 | > +--------------------+ > > On 7/7/2010 12:20 PM, Roderick A. Anderson wrote: > > On 07/07/2010 09:15 AM, A. J. Giurato wrote: > >> OK, Dovecot is showing those folders correctly from telnet. > >> > >> However, I can't subscribe to them in Thunderbird 3.0.5 (they don't even > >> appear) and I don't even know that squirrelmail 1.4.13 has a subscribe > >> feature. > > > > You did "refresh" the Folder list ... right? This has bitten me several > > times. :-) > > > > > > \\||/ > > Rod >