I have an old LanCity Cable modem too, but it's tricky to uncap it with my setup. I use Windows ICS to network the computers in my house, and the process of uncapping it becomes a little more complicated. I don't know if I can even do it, but I haven't invested the time to figure it out. I never upload data anyways(or have a need to upload faster than 32KB/s). My friend, who happens to be on the same node, has his LanCity modem uncapped. He uploads as fast as he downloads, 1.5 Mbits/s.
A great advantage to uncapping it is that while an upload is going, ping times to game servers do not decrease. Prior to uncapping it, an upload would kill his ping times. The bad part is, I swear he is sucking all the juice out of my node. He's some kind of FTP jock, always uploading and downloading. So please, don't uncap your modem unless you upload alot. Don't suck any more bandwidth out of our already over taxed cable networks!