I'm back yet again with a DIFFERENT problem now. Tonight, I tried to ssh into my pi over wifi (as I've been doing every day for the past two weeks), and I wasn't able to connect to it. I logged in to my router's admin panel, however, and it says that the raspberry pi is connected to the wifi, and I can use the router's "test connection using ping" feature to ping the pi. However, I can't ping or ssh into the pi from any other computer on the network.
To make it weirder, if I plug in a ethernet cable, (I'm able to ssh, even using the pi's wireless IP, if there's a cable), and I check ifconfig everything looks normal; wlan0 is up and running, and transferring a small amount of data (about 1.7 KiB), while the ethernet is transferring the rest. When I unplug the ethernet cable, however, my ssh connection is dropped and I can no longer ssh or ping the pi.
Do you know what might be going on this time?