That's right, the .limewire folder is your main LW preferences. Interesting that you got a totally different down result for the 2 speed tests.

(a) How old is your modem & (b) how old is your router?

I wonder if you tried a different port whether that would help. But that might require port forwarding.

From your isp FAQ: Most customers have a bandwidth limit of 2mbps. This doesn't mean you'll get any where close to that speed for actual downloads. You can only download something as fast as the slowest link between you and a server. The readings you get from speed testing sites will vary greatly which is normal. The download speed you obtain depends on network traffic (outside the cable network) at the time your actually downloading the test data. Since this congestion greatly varies, your line speed measured will be different every time. It is normal to receive reported speeds from <100kbps up to >1.5mbps, and an average of slower speeds during peak Internet usage hours.

Your isp Terms of Service

You use a router so I presume you connect more than one computer. How many?