QUOTE
Error in maketexting "Archives [Monthly]": Can't locate object method "Monthly" via package "MT::L10N::en_us" in bracket code [compiled line 2], as used at lib/MT.pm line 1105
It would not let me view the Templates page at all. I had to go into my database via phpMyAdmin and rename the templates so that they didn't use square brackets.
I can reproduce this bug by creating a new template which uses square brackets in the name, then attempting to view the list of templates in the MT interface, but if you want to check this out for yourself be warned: you'll need to use phpMyAdmin or similar to delete the template's entry from the MT database to regain functionality.