Since you request an answer, and I am terminally bored in the office today trying to read a 2" thick book about Penetration Testing, here goes
Fundamentally in answer to the question, yes, you can have both WLAN and fixed.
You have to log on to the router (done through a standard browser), go to the Wireless LAN section, configure the WLAN SSID to something memorable (shouldn't be left as default), and then preferably set it to "hidden".
Then go to the security tab on the router and select your chosen level of security.
At the moment WPA with a security key of 21 bits is considered "unbreakable" (within a reasonable length of time).
Avoid WEP, to a hacker it is virtually non existant as a security protocol.
Once all this is setup go on to the laptop set up the Wireless LAN settings to match the ones on the router and "Hey Presto" you're connected.
Of course, if the router was delivered by one of the Broadband suppliers here in German, one or all of the above may be redundant, impossible, or possibly just wrong.
But this is all explained in the "Betriebsanleitung" which is supplied with the router.
So, if anyone would like help with this topic in the future please either, post on the Forum providing extremely specific details of your problem or, buy me a beer, and I'll see what I can do over the phone.
So... we set the SSID on the router and can see that on the Windows XP laptop. We set the security protocol to WPA2 with pre-shared key and matched this setup for the wireless config on the laptop and of course entered the same key. The laptop sees the SSID/router, but tries to connect for a minute or two and eventually one of two things happen. Either it fails and the laptop has no IP address and the media state is listed as disconnected (using ipconfig /all) or the laptop gets one of those autoconfiguration IPs of this variety (Autoconfiguration IP Address. . . : 169.254.4.22). That's useless and doesn't connect me to the router. UGH.
It seems like something other than the security setup is not right because we tried WPA, WEP and open and got the same results trying all three. I also completely disabled the XP laptop firewall (temporarily) and again, no change.
Any ideas why this isn't working??? Incidentally, I've used the laptop at a couple of coffee shops which offer WLAN access recently and it always worked like a charm. No special configs were needed.
I'm starting to wonder if the problem is with the Speedport!?!?