@Shawn. Yeah, those little blue bastards aren't my favorite modems. Albeit, they do work. But you're kind of screwed on retrieving basic info for a bit of analysis. You're stuck with having to call in, unfortunately. If you do call in, you could just request them to check your modem, and give you the downstream/upstream numbers and post them here. But if there is something wrong, you'll still need someone to come out anyway.
@Eli: Yeah, it could be better. And if you seemed to notice that it started after they reconnected you, (if they did physically disconnect you as well) they could have reconnected you in a very un-cool manner. Or, since you have basic cable, they could have put a trap on your line that isn't the best (assuming something about your area). You've kept the same modem?
I would say Eli, that the only way you will actually get fixed, beyond checking your connections yourself -- is actually having a service tech come out, otherwise you're in the dark -- no matter what I, or the silly people in the call centers tell you. You will call, and they will tell you numbers and get "graph" readings and they will be ignorant about it. They will also probably tell you your modem probably needs replacing, which it may be (from my experience, only roughly 5% of the time). So, don't take my words to heart, but what I can tell you is, that your levels, usually from my years of experience usually indicate something being a little bit amiss.
ONE MAJOR POINT: Do either of you (only applying to basic cable connections, if there is a digital box, then it doesnt apply) have any weird ghosting, lines appearing on channels 2, 4, 7, or any of your other possibly broadcast old school antenna fashion channels?