Problems with wireless internet signal (10 pts. best answer)?

I have a problem with my wireless internet use. I have a Toshiba Laptop with a built-in wireless card and cable hi speed internet at home. I mainly use firefox as a browser but the problem occured when I was using internet explorer 7 as well. I have a SBG900 Motorola Cable Wireless Modem and Router in one. In the lower right hand corner of my computer screen, I can see that the wireless signal has been dropped because I just have a computer instead of the computer with the globe on top. I hover over it with my mouse and it says "Motorola Local Only". Why does the signal keep dropping and interfering with my wireless internet usage even when I am in the same house as the modem? The modem is only a 2-3 months old. I click on "diagnose and repair" and it either says windows didn't find anything wrong with my connection and then the globe reappears or it says something is wrong with my tcp settings and then "fixes" it and says that all is good but yet the problem recurs. Help!