so for the last while my wireless card has been acting up _sometimes_, on certain wireless networks but not others. I finally got a clue as to what might be going on: wireless N. It's an N card, but the driver/kernel stuff going on in ubuntu has a known problem with certain wireless cards.
Edited my modprobe.d/options.conf with the line:
options iwlagn 11n_disable=1 11n_disable50=1
and then (hopefully won't have to restart) ran:
sudo rmmod iwlagn
sudo modprobe iwlagn
And that seems to have improved things. So far.
#facepalms: like a lot. Until now. Hopefully.