account lockouts RADIUS?

User account gets locked out. In the time it takes to unlock the account,
click ok, and then reopen the account properties, the account is locked out
again.
We are using RADIUS with and esoft firewall (proxy and pop server on the
firewall).

The following can prevent the account from getting locked out.
1. Stopping the IAS service. Starting the service and lockouts resume.
2. Unplugging the patch cable from the NIC of the computer in question.

This morning I had the user type in her password after rebooting the
computer and told her to click OK to logon right as I clicked Ok to unlock
her account. She logged in and worked fine the rest of the day.

I have noticed a type 3 logon failures in the logs but I cannot be sure of
this as the cause.
All drives are deleted and then mapped again in their logon script.
Net use f: /del
Net use f: \\server\share

I have had this problem with several users.
Appears to occur on 2nd day after a password change, but I can't find any
cached credentials and why 2 days? and why does the problem return after a
couple of days after you have gotton beyond it?
Wierd.
Thanks for any suggestions.