Samsung forum: tuner problems with samsung LN40A650

Yes, i know about the 'air' and 'cable' mode.
In fact, i had started the samsung rescan for both (read properly) BOTH the 'air' and 'cable' mode.
It obviously (Read OBVIOUSLY) found the channels provided from by cable company, however no air channels were detected.
When mode is switched to 'air' then it gets no channels, though when switched to 'cable', the ones provided by the cable company can be seen, and when switched back to 'air', no channels.
What i mean to say in short above, is that i am a techie and not an IDIOT or a lay person.

As already mentioned in my previous post, no air HD channels were detected.
As indicated by "www.antennaweb.org", all the transmission towers are within 6 miles of my residence.

The point is that if the in-built tuner cannot catch signals being this close to the transmission towers, what use is the tuner for?
Why does samsung put them into the tv, and folks like us unnecessarily pay for the tuners when they are completely useless.

Thanks for any helpful tips in advance