Here is a late update.
2 computers ( well actually one, I do not call PECE for computers)
and a Apple Powerbook of cource!
In the DIR 655 logg I can see many restarts and the PECE never connects back again after a restart.
The Powerbook does..

I googled " DIR-655 wireless restart.
So many hits! Must be a hughe DLINK-problem.
(DLINK technicians napping on the job?)
I unticked "enable auto channel scan", after reading some Google-hits.
Now there is no wireless restarts in the logg and the PECE is working fine.
So I must add an "E"
A:WZC to "off". (or disabled) (Wireless Zero Config)
B:Upgrade to SP2 perhaps even SP3,
so that "no certificate" pop-up-window is gone 4-ever. (SP2 and 3 is containing the certificates.)
C:Make shure not 2 of "Wireless connection" applications are active at the same computer.
D: "lock" the MAC-adresses and IPīs in the DIR-655
(SETUP->NETWORK SETTINGS and there "DHCP Reservations List")
E: Disable "auto channel scan"
Now we might have a working DLINK product..