Ugh same problem here.
Just installed RCN last week in a wake of AT&T DSL cap announcement.
Speed test was great for just the first day (maxed out at 10mbps). Download speed is average 1-2 mbps. Yea, I might be lucky to see 7-8mbps at 2-3 in the morning.
Upload speed continue to max out at 700-800kbps.
These clowns seriously oversold their "fiber optic" capacity. I called the tech support and she tried to put a blame on my "firewall", "router", and my computer. Eventually she said she need to send someone in to take a look and if there's any problem on my end, there will be $49 charge on my account.
WHAT? It used to work great on the first day, and now 3 days later you're saying that there might be something wrong with my wiring? *sigh*.