I have noticed a dramatic difference in Wi-Fi on my iPod Touch after installing the 2.0 software. I am really unhappy. I have two laptops that connect fine everywhere in my house. However immediately after upgrading to 2.0 my iPod drops the wireless all the time. It will stay disconnected until I turn Wi-Fi off and then back on under Network Settings.
I tried changing the channel on my wireless router but it has not made a difference. There is something absolutely wrong with the Wi-Fi capabilities in 2.0. I had my iPod Touch for 5 months before doing the upgrade to 2.0 and the wireless never dropped in my house. My neighbors are not very close so I seriously doubt there is interference from another router (and no 2.4Ghz phones in my house). My laptops show an Excellent signal with 802.11g.
I am going to call Apple and complain.
Last week I noticed that my Touch would regularly lose its connection to the internet (the little wireless indicator would disappear and the only way to get it back on was to go into Settings > Wi-Fi Networks > "Choose a Network"). Then it started getting worse. I would follow the above process but would see NO networks. I would turn the Wi-Fi slider off, then on, and usually on the first or second try it would display networks. Somewhere in this process the iPod quit asking me if I wanted to join availabe networks in the app (the little pop-up of availabe networks quit appearing). Friday night a friend called to ask me for a phone number and I ran Safari, got online via the above, lengthy process and little did I know, but that'd be the last time my iPod would go online.
Saturday morning I woke up to check my email via iPod and it said no networks available. Normally in my apartment I can see 3, one of which is mine. I manually entered my SSID and was informed that iPod was unable to connect. Then I walked over and rebooted the router, still no luck.
The following also had no results:
1. I "Reset network settings."
2. I "Reset All Settings."
3. Restore from backup via iTunes.
4. Turning off "Fetch New Data"
The following allowed me to see my home network exactly one time (but still didn't let me connect.)
1. Settings > General > Reset > Erase All Content and Settings
2. Restore from back-up
3. Settings > Wi-fi
My network SSID appeared exactly one time, though neither of the neighbors wireless did. I clicked on the name, and got "unable to join..." at which point the SSID disappeared from the list. (which now only says, "Other..." and refuses to join my network when I enter the SSID and the iPod is SITTING ON THE ROUTER!")
I'm now at work and the WPA network at work also doesn't show up. Normally from my desk I can see 3 networks.
At home, I've got (at this point) an unencrypted, SSID-broadcast, non-MAC filtering network that works for 5 other machines in the house. According to apple my Serial Number is not worthy of free technical support so I'm appealing to the masses here with some hope that this is a simple procedure that I'm missing. If this is really a hardware failure of the iPod at 11 months there's some serious quality control issues!
http://discussions.apple.com/forum.jspa?forumID=1215&start=0
There are at least half a dozen threads (not counting the "i can't configure my wireless, help!" posts) with people having issues of little or no wi-fi in the last week, seemingly out of the blue.