Hi, I'm way late to this discussion, but wanted to chime in for what it's worth. I've had three devices hooked up to wifi on my home network for three years: a Toshiba laptop, an iPhone 2G (first generation iPhone) and a Dell laptop. All have worked with my Netgear router with no issues whatsover, all received excellent signal strength. Got my iPhone 3GS a month or so after they came out and deactivated the phone service for my first generation, but kept it for my son to play games on (basically made it an iPod Touch).
Started noticing my 3GS was slow on my wifi, but thought I was imagining things. Noticed I was getting a really weak signal (just one "bar"), but just kept switching the networking off while at home and using the 3G network to read, listen to Pandora, etc. Finally read some threads on some other blogs by others with the same problem, who thought it was the networking chip. Didn't have time to do anything about it until this week... Recall that my first generation iPhone was still getting full strength signal all the while.
Went to the Apple store two days ago to talk to one of their "Geniuses." First guy told me I needed to restore my phone, so I went home and did that. Same issue, no resolution to the problem. Went in again and told them my problem, and a different guy told me I needed to change my network security protocol from WEP to WPA. Said he went through the same thing, and it was my security protocols or my router itself. Told him no, my router has been working fine for 3 years (including my first gen phone) but I would go home and try.
Went home and changed my security. Same issue, no resolution to the problem. Now, of course, I'm ticked. I know it's the chipset (I'm no techie, but come on). Took pictures of my first gen iPhone sitting right next to my 3GS, showing the old phone with a full strength signal. The 3GS? At first it showed only on the 3G network (even with the browser open). Finally it picks up a signal, but only one of three bars... all sitting about 4 feet from the router.
Go back to the Genius bar and show the guy my pictures. Also had changed the security settings on my Toshiba and my Dell laptop... all three devices (first gen phone included) still work great, but not the 3GS. Guy has the nerve to tell me it's still my router and recommends a new one. BUT, tells me that since I have "photographic evidence" he'll give me a replacement phone. I take it home, set it up, and guess what... same problem!!!!
Tell me it's not the phone! I've been Apple's biggest salesman ever since I got my first iPhone, but I'm just a dissatisfied customer who feels lied to and subjected to a corporate cover-up at this point. Just wanted to let you all know, so you know that you're not crazy. It's the phone....