Has anyone had this happen with an MICB?

We have an Option 11 with Succession 3 software. When we installed an MICB comference bridge, it kept generating XMI001 and XMI002 codes (polling fails, then re-establishes). A Nortel guru told us to connect a TTY to the card to monitor the MICB software, and the XMI codes stopped. Now, as long as a TTY is merely connected, with the TTY turned on or off, there are no XMI codes and the MICB does not fail polling (works properly).