wrote:
Can you sum up the problem with conservation of energy that modern RF
textbooks get wrong?

They don't get it wrong - they just don't discuss it at all.
But here is an example of the problem:

http://eznec.com/misc/food_for_thought/

First article - last paragraph. W7EL considers
steady-state conditions while ignoring the previous
transient state conditions. He implies that the
energy in the reflected wave cannot be recovered but
it is indeed dissipated as power in the system after
power is removed from the source. The source supplies
exactly the amount of energy during the transient power
up conditions needed to support the forward and reflected
waves during steady-state. This is easy to prove. But
W7EL's Ivory Tower protects Him from peons like me.
--
73, Cecil http://www.qsl.net/w5dxp