Connects at boot, but disconnects at logon

Hi,

I have a wifi network with 802.1x setup. I copied the certificates to two
different locations: one set for the computer account and one set for the
user account.

When my pc starts, it connects to the wifi before logon using the computer
account certificates. When I logon to the (samba) domain, all startup
scripts from the server run fine. However then the wifi connection is
disconnected and does not connect automatically (at least not immediately).
I have to repair the connection and then it works perfectly as long as I
want.

How can I force that the connection does not disconnect at logon? Or maybe
there is another solution?

Thanks in advance!!!

Ernie