Bug#334798: screen position

[Justin Pryzby <justinpryzby@users.sourceforge.net>]

I'm more convinced than ever that this is a blackbox bug.  When the
window shifts itself to the center row, the position which blackbox
indicates for the window is: 2147483647 aka INT32_MAX.

Not only that, moving by one pixel changes the X position to
2147483647.  The Y position is never really visible, since the X
position takes up so much space .. but it appears to work as expected;
0 at the top of the screen and 700 at the bottom.

Still can't fathom why it only happens with firefox, though.