Wireless adapter seems to slow down immensly

My wireless adapter, after a few minutes of being plugged in, seems to just bite it, slowing down everything. My Steam downloads go from the usual 800KB/s down to 50KB/s, skype takes a huge dip, and web pages won't load. I unplug it, and plug it back in and it works like it should for about 30 seconds. Here's the adapter:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I've tried the following:
-Uninstalling and reinstalling drivers
-Different computer
-Different USB port

Not sure if this is the right forum, but I couldn't find another that suited the issue.