maverick: I have seen the same same for Cisco PAP2-NA's that's why we ban them from our network..... Being sold by some scum dealers on trademe for next to nothing.
No help from Trademe when pointed out to them I must say , they weren't interested, not a fan of trademe anymore as they were happy to let customers buy known counterfeit devices
There were issues with ex Vonage SPA devices as well that all had the same MAC. The only way they could get around the service provider locks was to do some sort of reflash that game them all the same MAC. Genuine Linksys device but hopeless for all intent purposes!