USB wireless adapter, fast through cable, slow through direct

(This is a desktop computer, not the one I have for the forums. Windows 7 Professional)

I have a wireless adapter (WG112v2 ) which plugs into a USB slot. For some odd reason while plugged in directly I get slow speedtest.net readings, 4Mbps; yet while run through an extension cable of three feet I get speeds around 20Mbps.

Seems like possible interference, but I would think the connection would be spiking rather than a persistent lower speed.

My internal wireless card was giving the same slow speed readings until recently. I did some disabling/enabling and the speeds received are normal again. It does appear to be receiving spikes however while the USB adapter does not.

It gets better...recently (today actually) my connection has been dropping from a game consistently, every minute about, while a direct cat5 connection works fine. Each disconnect seems to disable my entire internet briefly. Is it possible for a non-malicious third party application to cause this?

In the end, I'm really confused. I want to say it's router related but I doubt that is the case given the odd complexity of problems.

PS: I'm using a wireless keyboard and mouse if that matters. Microsoft Wireless Mobile Mouse 4000 and the HP Slim Elite keyboard.

Hi vpwin7,

You may try changing your router's Wireless Mode, usually it's in Mixed Mode, try a B/G, G or N (if it supports).