Dam wireless

I am having some issues with my Thinkpad. It is not doing wireless very well. I had issues yesterday in a meeting. I had no signal where I normally get good signal. Then last night the dam thing got low signal while I sat at my desk at home. I sit right over the dam wireless point so why did it have bad signal while my mac got great signall? Well, I have no idea. My netstumbler (a wireless signal and network meeter software program) also showed poor signal quaility. I need to check signal streangth with another laptop with netstumbler. if it is fine I have a bad wireless card. If it is bad, then something is wrong with both networks at work and home. That is unlikely.