found my own answer, so for others, here is the info:
BlackBerry Device Software version Media card size limit
BlackBerry Device Software 4.2.0 Up to 2 GB
BlackBerry Device Software 4.2.1 Up to 4 GB
BlackBerry Device Software 4.2.2 Up to 4 GB
BlackBerry Device Software 4.3.0 Up to 8 GB
BlackBerry Device Software 4.5.0 Up to 8 GB
BlackBerry Device Software 4.5.0.81 and later Up to 16 GB
BlackBerry Device Software 4.6.0 and later Up to 32 GB