hi Pat,
view these results:
http://www.webpagetest.org/result/110110_76_86W9/
http://www.webpagetest.org/result/110117_ZY_7971067d2b21129278cd7f6eecce415c/
The Start Render calculation cannot be correct.
It comes right after the HTML has finished loading, and before CSS and other objects that are in the HEAD of the HTML. To my knowledge, the browser cannot start rendering until it is done processing all that is in the HEAD.
But this does not occur with all tests from that location, e.g.
http://www.webpagetest.org/result/110118_2T_9PD/
http://www.webpagetest.org/result/110118_88_96E/