I got a Kyo TA420 installed on a W2008 R2 64 bit system. All options available (A3, mailboxes,...)
When connecting printer locally on a xp system, no problems , all options available.
However, when users log on a terminal server session, there are 2 possible printer connection methods : connecting by mapping with RDP session or adding printer on terminal server profile,
in both cases , user cannot select A3 paper format and they cannot select mailbox output.
Both server and clients use the kx driver.