It's subject to interference from neighbors, sun spots and more. Nice when it works but the makers have done a poor job explaining how interference is something we can count on.
To help it along, try the settings noted in the forum sticky.
I use a 802.11g wireless card with a Belkin F6D4230-4 router. I don't know if it's of any importance, but my OS is Windows XP. The problem is, I often get slow speeds like 1, 2, 5.5 Mbits/s when I usually get 36+mbits/s. I tried changing the channel, and it didn't fix my slow speed, it only made my computer freeze. Also, I doubt it has something to do with interference as I can have a good speed for days and all of a sudden it drops to 1mbit/s for no reason, for days too. That is, when my connection works and doesnt just crash.
If anyone has any idea, anything at all, tell me, please.