Duplicate entries in registration list!

The other day one of the clients (Broadcom based) lost connection and I had to re-configure it. Still it wasn’t able to connect, so i finally rebooted the AP (BTW RB333 with rc13 that has run for 55 days!), in the same operation I upgraded to 3.1.

Now the client connects fine, but as you can see it appears twice in the registration list. Tried to remove one of the entries, then both disappeard and the client re-connected all fine.
But after a while there is once again a duplicate!

Why is this?
DupReg.jpg

we need the support output file from that router where you see those dublicate macs.
What client device it is and in what wireless mode?

please send that file to support@mikrotik.com
Aslo make sure to upgrade to v3.2.

Looks like upgrading to 3.2 did the trick.
Will observe and eventually revert.