I was having the same trouble with RP accounts until a friend pointed me to this (http://ljlogin.e-space.gweep.net/), it's a Firefox extension that lets you switch between LJ accounts by having a list of them appear on the bottom toolbar. You just click to a different name, reload the page and you've switched account.

And hey, you lasted longer at Nano than I did. I got ill on like the third day.