It's been a while since the complaint and I've been working on it. Now I am sure it's not D-Link's fault. Just the amount of posts by people with Macbook pro's and weird network trouble is overwhelming. Check out this thread:
I haven't been able to solve it and it's driving me crazy. It seems to be a software issue related to the Airport extreme card. Changing the card has been useless to many.
If ever manage to fix it, I'll post detailed instructions. I promise.
I hate Apple right now. The first post in that thread is more than one year old (and several Software Updates --up to 10.5.6-- and specific Airport Updates --last was 2008-4!--).
Fortunately the problem only occurs in the office (ha) and never at home!