If you use comic sans ms, it adds the coding for the font and doesn't even make it comic sans.
Example:
[font='comic sans ms']TESTING[/font]
It also doesn't work for
[font='arial black']arial black,[/font][font='times new roman']times new roman, [/font][font='andale mono']andale mono, or [/font][font='trebuchet ms']trebuchet ms[/font]
Verdana, arial, courier, and georgia seem to be fine though