Here is a small list for you. Of couse, corrections are most welcome:
Routers that don't support fully support CIDR:
ASCEND Pipeline and MAX products
Telebit Netblazer
Livingston Portmasters, and possibly IRX routers also.
Yes, add the IRX's to the list. Tho Livingston says they are working on it.
Nathan Stratton CEO, NetRail, Inc. Your Gateway to the World!