[CRASH] assertion triggered when scrolling down Tutorial.lyx

[Abdelrazak Younes]

1) Open Intro.lyx
2) PagesDown 5 times

The following assertion is triggered in text2.C:994 (LyXText::editXY()):

        // This should be just before or just behind the
        // cursor position set above.
        BOOST_ASSERT((pos != 0 && inset == pars_[pit].getInset(pos - 1))
                     || inset == pars_[pit].getInset(pos));


The problem is that at pit=13 and pos-1=317 we have
  inset != pars_[pit].getInset(pos - 1)

Anybody understand the problem?

Abdel.