A few months ago I switched from a Time Capsule setup to an Airport Extreme + external hard drive setup, to do Time Machine backups. I completed a fresh backup, and everything has been working fine. Then yesterday, I started having some problems connecting to the Airport Extreme. Airport Utility popped up, though I still had Internet access. I successfully updated to the new firmware after a few tries (the download kept erroring out for some reason) and set a new Airport Extreme base station password. Now today, my computer had trouble connecting to my backups. I reselected the disk and agreed to create a fresh backup, and a short time later I got the error message that is attached. I restarted the backups again, and now it's going (for now). What is going on with my system?