A while back I had reported difficulty with the reliability of my wireless connection. I learned that different channels may perform better than others, and by switching, my wireless connection is much more reliable.
There are also various tools that can help the educated person with their wireless network. NetStumbler is one such program. With NetStumbler, you can test the signal-to-noise ratio (SNR). The higher, the better (i.e. a lower number is bad).