This might be a case of a network using 40MHz wide channel. I have personally experienced the same. it's faster for 802.11n, but it drops legacy support for 802.11b/g, which uses 20MHz wide channels. Unfortunately, we do not yet have 802.11n support. I may work on it eventually.
Are you saying that networking hardware that drops support, now can interfere? (That there's hardware out there.. that will interfere) ? Like if a vendor's wireless router was only tested for "homogenous conditions" ? ... Something like cookies in tcp/ip? (that exploit [sic]) could occur? So they drop support, so they can sell a 'non-compliant' technology. If it uses less chips, they can claim it's improvement on an existing patent.