using analog lines for data transfer is fundamentally limited due to a lot of factors, some of which I will list out:

-noise
-electromagnetic interference
-obselete cabling
-bad connectivity
-anything and everything else

So basically clout's right when he says it's out of your hands. If the speed is restored in time to 46-49kbps (which is pretty darn good speeds considering) in time, then I don't see a reason why it should be obselete cabling. I think it's more of the first reason more than anything *nod*.

I am not 100% sure whether analog/voice cables have anything better than category 3 going on with them, but as far as I know, if they don't (which I think), the cable lacks anti-magnetic measures, and thus, it's more than likely that it's electromagnetic-interference related. Why it fails when you 'reconnect' is beyond me, and I'm definitely confused over the 'getting the phone worked on outside'