I spent 2 days reading through forums, searching Google, talking to clueless B & N tech support people, and even emailing the Netgear tech support department before I finally figured this out. First, let me say that most of the problems that I've read about appear to be with Netgear routers, which is what I have. Specifically, mine is a Range Max N-150 wnr 1000 router.
Most of the posts that I read seemed to be focused on the security being used by the router i.e. WEP vs.WPA-PSK or WPA2-PSK or both. And while it is true that if you set your router security to "None" the Nook Color will work, but that is not a viable solution in my opinion. Why would you jeopardize the security of your entire network just to get an e-reader to work? No way.
Here is what does work. You need to change the mode (speed) of your router to 54Mps. Mine was set at 65 Mps, which is the default setting from Netgear, but the Nook Color will not work at this speed. As soon as I changed this setting the Nook Color connected to the internet instantly and has had no connectivity problems since then.
Here is how to do it:
1. Log onto your router using the IP address assigned
2. Click on the Wireless Settings link under "Setup"
3. Click on the drop-down menu for "mode" and change the Mode to 54Mps
4. Click "Apply". If you skip this step the change won't be made
That is all it takes. I was somewhat hesitant to drop the speed of my network, but my internet actually seems to be running faster on the entire network now - bonus!
Why B & N can't troubleshoot this and spread the word to their tech people is beyond me. They actually had me return the first one that I bought because the tech guy said it was defective, but I'm sure that it wasn't.
This solution worked immediately for me and I was able to keep my WPA-PSK + WPA2-PSK security intact with no changes.
Well I hope this helps some poor soul who is as frustrated as I was during the last few days. I really appreciated the comments that others have posted although most are way off base so be careful about some of the advice offered.