The fact there is only really 7 channels when taking overlap into account, does make it somewhat difficult if there are a lot of routers in the same proximity on close channels.
For a better explanation (which probably contradicts what I just said) check out http://en.wikipedia.org/wiki/IEEE_802.1 ... patibility.
If there's other access points in range, this makes it somewhat difficult, even when on an open channel you will get interference from other channels parallel to the channel you're on.
If you don't absolutely need wireless, go wired, as it's a far better and more secure solution. Even a perfectly configured wireless network can go night night with interference from other devices in nearby range.