View->PDF (pdflatex) vs View->Update->PDF (pdflatex)

[Allan Rae]

Viewing requires one run of pdflatex.  Updating runs pdflatex 6 times
using the exact same file -- no changes in between runs.

Allan. (ARRae)

P.S.  Just in case you're wondering why the flood of reports, I'm working
on the LyX presentation for CCP2000 which is on Wednesday morning.  
Nothing like leaving it till the last minute for that extra thrill.
I'll make the slides available as soon as I've finished them ;-)