Clearwire Speeds Hot in the AM, Cold at Night

Compare this smokin' speed from 6:00AM this morning:

http://www.speedtest.net/result/1160027663.png

To this speed at 9:46PM:

http://www.speedtest.net/result/1161091027.png

This is consistent. Every morning, speeds are what Clear promised when they sold me my service. Fast. At around 8:30AM every day, the speeds change, as though someone flipped a switch. In the evening, the speed is always pitifully slow. Every day.