Sitecom wl-105b AP en sitecom D201 do not communicate

Hello,

I recently bought a sitecom wl-105b accesspoint and trie to connect it
to my excisting D201 router / switch. The ap has IP 192.168.0.250, the
router has ip 192.168.0.1, both devices are in subnetmask
255.255.255.0.

Via an pc, connected to the router, i can reach the AP at first. But
when i make any changes (password, channel, MAC adresses and so on),
the AP is no longer reacable through the PC.

Via an DELL Inspiron 5100 laptop with dell true mobile 1300 Wlan card,
an wireless connection is build to the AP, but only the laptop sends
packages of data to the AP, the AP does not send any back.

From the laptop i can't connect to the router, even an ping session is
not succesfull.

The AP is on firmware 1.37, the router on 1311. Both the pc and laptop
are installed with XP Home.

Perhaps a bit of a long story, but i hope someone can help me.

Kind regards,

Erik Schakenbos
(E-Mail Removed)