Can I connect an AP directly to a PC?

Interesting one this... I have purchased a Linksys Wireless-G Access Point
(AP) and connected the LAN socket on it via Crossed Ethernet cable to my
PC's LAN socket.

Although the AP is successfully broadcasting my LAN around my home now, and
indeed I have locked Microsoft's Media Center Extender set-top-box to it and
can now stream TV shows from the PC, I have a problem...

The Linksys Setup CD will not run. Exact error message:

"The Setup utility was unable to locate an Access Point on your network.
Please make sure your Access Point is powered on and any cables are properly
connected."

BUT, sometimes (and it seems very random) if I use a straight, uncrossed
cable, I can get into Setup and configure the AP. The only problem then is
that the PC reports that "This connection has limited or no connectivity".
And indeed with this cable I cannot access my network from my Wireless-G
laptop.

So, to summarise:
A) With a crossed cable I can broadcast my network, but can't configure
the AP
B) With a straight cable I can't broadcast my network, but can configure
the AP!

Also, with 'A', if I attempt to connect my Media Center Extender, AND laptop
at the same time, my laptop won't connect and I get the limited connectivity
error again With my Wireless Router, this was not the case and I could
access the LAN from both devices wirelessly simultaneously... I think!

Also, with 'B', although I can run Setup (occasionally!) it is only the old
version that works, not the newer one on the Linksys site. Furthermore the
web-based config utility accessed via 192.168.1.245 shows no page found.
Further-furthermore, pinging that address gives Destination Host Unreachable
or Request Timed Out errors.

Ultimately, it works. But I'd really like to allow my laptop to connect
simultaneously and be able to configure advanced options via the web
interface.
--
Thanks.

CJSnet

(Remove TEETH to reply by e-mail.)

PS: I have tried all the steps, patches and fixes listed at
http://www.pchell.com/support/limitedconnectivity.shtml