Wi-Fi disconnecting randomly
This is not always a huge problem, but sometimes my Wi-Fi (in Ubuntu Lucid) stays connected all day and sometimes it disconnects a few times per day - my Windows laptop stays connected all day, so I don't think there is anything wrong the modem.
To reconnect in Ubuntu, I just have to disable networking and enable again and the connection is back within 10 seconds. Not sure why it would drop off though? It can be a bit of a pain if I am remotely connected to a server and it throws me off.
Maybe there is some strange setting that I can change, but I certainly don't want to make things worse when it works most of the time!