Wanting to understand how fastrack plus works when using the default quick setup method for N900

Our old TDS modem died and was replaced with a new one with only the WAN port. I bought the NONE & hooked it up as noted. While browsing and downloading do work, browsing, especially watching videos while downloading, does become slower and videos cashes more often. I was under the impression that fastrack automatically kicks in when downloading and surfing at the same time. If this is not true are then any tutorials which will help me understand the setup & concept better than the manual?

64bit WIN 7 PCs

Power PC G5 Mac

Ipad 3

Hi, just to do a test go to the N900 dashboard and disable the fastrack.