Significant reduction in Airport range

I have a powerbook 1.33 with an airport extreme card. Recently I have found that the range of my reception has declined significantly. I still get a signal but I can't move into another room without loosing it (this happens at other places besides my house.... school, friends houses, etc). Anybody else experienced this?

Well...

While I have never noticed a sudden loss of signal strength; my powerbook always has much weaker signal than my windows laptop with a linksys pcmcia card.