Ron wrote:
I expect that the support bracing is bent and if you straighten it the
problem will go away. Sounds like someone was a little rough with these
sections.

Nope, the bottom of the tapered section is the
specified 11.25". Somewhere between the beginning
and end of the 4" tapered section is where the
problem occurs. And two sections are virtually
identical which would seem to rule out any
accident.
--
73, Cecil http://www.w5dxp.com