Secondary IAS Problems

We are in the process of adding a secondary IAS server to our LAN in
order to overcome the 50 RADIUS client limitation that we have hit (I
know we should upgrade to Server 2003 EE, but I would rather try the
second IAS solution first).

Key point in our network are:
- Windows 2003 server only
- All worktations are XP SP2 (managed through GPO)
- Cisco 1100 WAPs
- 802.1x authentication using primary IAS on DC
- CA running on same DC as primary IAS (no external certificates used)

A secondary IAS server (on another DC) with the same config as the
primary (except for different clients) has been created.

Everything works fine for wireless access through WAPs that use the
primary IAS, but on any WAP configured to use the secondary
authentication only gets as far as 'Attempting to Authenticate'


Has anyone had a similar configuration that worked succesfully ?

rod