[RCU] Upgrade 0.4.2 to 0.5.1 => Folders gone, cannot read mail; imap_root issue

Hi - I just upgraded from 0.4.2 to 0.5.1 and came across the following issue:

After upgrading, I ran the installer to test the config. The installer told me that "imap_root" setting in main.inc.php had been changed to "imap_ns_personal". So I replaced the imap_root entry with one reading imap_ns_personal - and did not see any folders anymore, and could not read e-mails anymore. After trying numerous things, I just replaced imap_ns_personal again with imap_root and ... it's working again.

Why? The installer is not happy with this change - but I am. :-)

Thanks!

List info: http://lists.roundcube.net/users/ BT/9b404e9e