I've realized that sometimes I "lose" my wireless signal. I am not using an AirPort router (I'm using Linksys, if that's at all helpful). I've noticed that suddenly all of the wireless signals disappear from the AirPort menu up on the menu bar, except the network that I am connected to (i.e., I only see my router's name there). It also becomes impossible for me to browse the internet, so what I've done to troubleshoot this is disable the AirPort, put the computer to sleep, and disconnect/reconnect my router. When I turn it on, it seems to work. I've also tried simply disabling and then re-enabling AirPort, but it doesn't work after that. Anyone else having this problem/something similar? Thanks for the advice, in advance.