While their updating stuff on your line (this is experience from NTL and their maintenace, because they do alot of it constantly in my area) for some reason it doesn't update very well your end, so like GenPub said, just reboot it and it should request new signals giving you a better connection.
EDIT: Also... be sure to ask the bunch of idiots at the other end (your ISP) if your modem ACTUALLY supports 8Mbps.
When they upgraded my line to 4Mbps from 2Mbps I had the NTL 100/120. Which
DID NOT support 4Mbit (only supported 2.5Mbit). Took them ages to FINALLY figure out what the problem was. Got a new box and all my net issues were instantly resolved.
