IAS not authenticating users

Hi,

I use IAS with PEAP to authenticate wireless users, my server
certificate had expired, so I deleted the expired one and issued a new
one. IAS is hosted on my CA and is server 2003. Now users are unable to
authenticate and event ID 20168 is logged into the syslog with the
following message "Could not retrieve the remote access servers
certificate due to the following error: No credentials are available in
the security package."

Any help would be great.

Thanks.