dovecot - Aug 2012 - Dovecot / Win8 Mail App Folder Subscription Issue

Win8 RTM Mail App now supports IMAP. I am running Dovecot 1.2.15 on a 
Debian Stable server.

The App works fine except the list of folders displayed seems to be a 
random subset of all my folders. I can't figure out how it's picking 
which folders to show, or how to change what's subscribed. Editing the 
"subscriptions" folder in ~/Maildir/ doesn't seem to have any
impact.

Any suggestions on how to troubleshoot or narrow done this issue?

I posted to a Microsoft forum but was told the Mail App will only 
support official email providers.