As we get to the final draft stages of the 802.11n standard, it was thought that the neighbor interference issues have been put to rest by the Draft 2.0. The new standard supposedly has a strict ban on dual-channel operation whenever any legacy devices are operating. The product is suppose to back off from 40 MHz wide bands to 20 MHz so that it isn't hogging most of the 2.4 GHz spectrum. The only problem is that it doesn't work according to Tim Higgins' tests. Without this functionality working, 802.11n products are simply a legal way to jam your neighbor's 802.11b/g Access Points.
The problem here is that consumers don't know that this causes their neighbor problems and even if they did, it "isn't their problem" since they're causing their neighbors grief. Furthermore this is an underhanded way of driving adoption of new 802.11n gear through an arms race. The intent of Draft 2.0 was to fix these serious problem from Draft 1.0 with strict operation rules but it seems that it simply doesn't work as advertised. Intel on the other hand seems to be doing the right thing with their Centrino certification rules that ban all 40 MHz operation in the 2.4 GHz band. The IEEE 802.11 standards body should be considering the exact same ban.