Crazy internet connection issues

Given the amount of threads I've seen about difficulties that people have had getting their iPod touch online using Airport from their Macbook, and the fact that there also seems to be a multitude of answers, can anyone list some of the factors that could be attributing to the various connection problems?

Im trying to understand my problem. I know that everything is right. But

sometimes it connects.

sometimes the symbol appears on my touch even though Im actually not connected (until mail or another program tells me "connection to the server has failed").

sometimes I get a warning saying "Unable to join the network...",

Sometimes Airport appears, other times not.

The last time it worked was 10 hours ago, just stopped while I was listening to the radio (on the iPod and writing an email on my Macbook, settings did not change during this). I have reset the network settings on my Touch several times, checked the IP address, at the moment its not working. What are the factors? Its making me crazy.

 

By "threads" I mean posts on various forums relating to iPod touch and iPad issues connecting with Airport. There are a so many potential solutions out there that it could make one's head spin (read: "making me crazy") and Im wondering what factors there are in achieving a successful internet connection between the device's built in WiFi and Airport. Just a general question.

The goal is only to start a discussion about the factors affecting internet connection problems.