HELP... Here's the situation, I have a D-Link router with three computer working off of it a PC desktop thats connected by cable, a PC notebook connected by wifi and my Macbook connected by wifi. Now every so often (like every 10 - 15 mins) I loose connection, it's still picking up the signal from my router it just has no internet connection. So what I've been doing is turning my airport card on and off and its fine for a little while. Anyone have any ideas before i entertain the thought of it being a faulty airport card.
"Part of me suspects that I'm a loser, and the other part of me thinks I'm God Almighty."
I had an oldish D-Link router which worked fine with all my PCs (a Dell Notebook running XP and Xubuntu, a PC running XP Pro and Ubuntu, an old Mac Quadra 950, a Quicksilver G4) up until I bought a Macbook. I had similar problems as you describe but less frequent - I had to reboot maybe every week. Very annoying and very wierd. The problems dissapeared when I bought a Linksys WRT54G and installed the open source linux based dd-wrt firmware.
The only thing I can recommend beside buying a new router is try using a static IP for you Macbook. It appears that maybe D-Link routers and Macbooks are not a good match?
I don't think it's OSX because, as I mentioned, I have a G4 on my network and I frequently work on a MBP from work. It's was only my MB (2.16mhz) that disrupted the network. I also have a bunch of other gadgets (Xbox, PS2, Wii, PSP, DS, iPod Touch, iPaq) that worked fine too. I think I had this problem when the Macbook was on Tiger too - I cant remember though.