Same problems as above. New Macbook, bought 1 month ago. Downloaded 10.5.1 straight away and then 10.5.2. In brief, my downloads would hang intermittently... download the 1st 50% or so of a page and then... take .... forever.... to ... download ... the ..... remaining .... 50%.
When this happened my wifi signal would drop to 3 bars (even though I was sitting 5 feet from my wireless router). Called apple, they said it was my D-Link router. So I went out and bought a NetGear. Same problem. Ethernet works fine on the mac, and PCs connected via wireless worked fine.
Interestingly it would affect some web pages more than others .... msnmoney.com seemed very slow. Occasionally Apple.com was also very slow. Called again.
"Well, we can't guarantee that your Macbook will work with any router except airport... but why don't you bring it in so a "genius" can take a look at it"...
In the store it initially worked fine, and I got "well, it seems to be within specifications now. I can't do anything for you"
Then I just sat there and kept web surfing until it happened. When it did happen, and I showed the "genius" that it was taking >60 seconds to go to google.com and my wireless signal had fallen to 3 bars, he said that it was just the load on their Apple store router and my machine was still within specifications! I couldn't believe it!!!
I just kept sitting there and stating over and over again that #1 every other mac at the store had full wireless strength and #2 no other mac was taking 2 minutes to go to google.com
I don't know If I wore him down or what but he said "this is going above and beyond the call of duty but we will give you a new Macbook (keep in mind my mac was less than 30 days old).
He also kept saying that my machine was within specs and that they can't guarantee any router except airport.
Anyway, I am typing on a new Macbook, I have not downloaded 10.5.2 (nor will I until apple acknowledges this problem), and overall I am extremely disappointed with the Apple in general. I felt like I was begging him to acknowledge this was even a problem. He simply refused to believe there was anything at all wrong with my mac.
This is my first Mac after having spent all my time with PCs (Tandy TSR-80 was my first). Unless something changes I can't imagine recommending Apple to a friend or ever buying it again, as I am just waiting for this one to crump out, leaving me stuck with crappy wireless.