dot1x, win2003 and machine + user auth

[odd.nielsen]

3550 running ios 12.1.22.ea1.a

basic dot1x config

dot1x system-auth-control

interface FastEthernet0/1

switchport mode access

dot1x port-control auto

spanning-tree portfast

!

and:

radius-server host radius_server auth-port 1812 acct-port 1813 key yeah_right

radius-server retransmit 3

Client:

WindowsXP SP1

Registry:

supplicantmode = 3

Authmode = 1

RadiusSERVER:

Windows2003 IAS

PROBLEM:

Client boots up, authenticates okey, user try to login, all okey, the client try to authenticate the user, the link goes down 6-30 seconds, then it goes back online.

[drolemc]

Could it be that the problem has nothing to do wiyh dot1x? I don't remember hearing of a flap problem in a dot1x implementation.