9MB = 72000000b/25200 = 2.8Kbps. There's still only 8 bits in a byte, overhead never changes that.

And 90Mb = 90,000Kb not 9000.
That is also an average, it could have been using much more throughput during a shorter period.
I honestly can't even figure out where I got that 160Kbps from originally. Maybe I used gigabytes or something but I can't even repeat that. I think I just divided by 8 or multiplied by 8 one extra time.
Some cable providers with data transfer caps provide a way to see how much data you've passed during a period.
It's doubtful that his own machine is 192.x. If it was, he wouldn't be able to access the Internet.
Based on the line from netstat, skinman2's machine is named "server", listening on 3155 and is connecting to a computer at 192.168.1.2. This is consistent with a trojan or other application connecting to a machine, which is this case happens to be someone on the local cable network since there'd be no other way for the two machines to connect. Because the cable network is shared in a certain way, the machines can see each other even though they aren't on the same IP network.
The WinXP firewall doesn't block outbound connections at all. So if this program makes a connection to a central server to route traffic through, then the firewall wouldn't do any good. The only time it would help is if someone tried to make a connection directly to you to transfer a file.
My guess is that whatever is running is connecting to the 192.168.1.2 machine as its central server. Then the connection just sits open to the server; the program regularly updates the server about what files are available; normally someone would use the server to find a list of files and if they wanted one of yours, would make a direct connection to get it. But since you're behind a firewall, they can't, and since the server is on a private IP nobody should be able to even see it.
First thing to do would be to check if that jpegmpeg is installed. Look in the start menu (check the startup folder while you're there), and check the Add/Remove Programs tool. If you can't find it and don't know about it, check the system tray to make sure it's not running there (you'll need to expand it if you allow XP to hide icons). Then run "msconfig" on the Run dialog and look at the startup tab. If you see it there, uncheck the box (you don't need to reboot immediately, it'll just stop it running next time you boot). Then hit control-alt-delete to bring up the task manager, and on the processes list, find the item named the same as whatever you found running and end task on it.
Then reboot. Check after a bit to see if it's running. If it's not, then you've stopped it working, and you can find the location and remove it. You may also want to download adaware from
http://www.lavasoft.de just to check whether you have anything else installed such as spyware, and also you should be running an antivirus program that keeps a background monitor. Having a computer always connected directly to a broadband service is just unsafe.