Well, with considerable help from our ISP, we’ve found out why our connection’s been wonky: apparently our modem has been hoarding IP addresses. It’s supposed to grab an available one when the computer comes on and needs one, then release it when there’s no longer a computer actively connected to it; but it hasn’t been doing that. Instead, it’s been grabbing them and keeping them—it’s currently up to four IP addresses, which has been creating a major traffic jam for our computers. The tech said he’d never seen anything like it; they’re having to bump this one up to the big technical guns to get it unsnarled. If all goes well, though, this should be fixed sometime within the next 24 hours, and the connection working properly again. That will be nice.