Stacking a PowerConnect 3424

Hi everybody,

I have a 3424's stacking and the question is:

The unit 3 is wrong?, I mean, there is some problem about this unit? or is normal that is unit have been disabled the master:

Unit  MAC Address        Software    Master       G3         G4      Status
----  -----------------  ----------  --------  ---------  ---------  -------
1     03:34:gg:xx:xx:xx  2.0.0.21    Enabled   2          3          master

2     02:43:gg:xx:xx:xx  2.0.0.21    Enabled   3          1          backup

3     04:21:gg:xx:xx:xx  2.0.0.21    Disabled  1          2          slave

Topology is Ring

Unit Unit Id After Reset
---- -------------------
 1            1
 2            2
 3            3

If yes, what can I do?

Regards&Thanks.