New bar makes new page when still room on first page (0.9.6 b1 r2674)

Hi

This problem existed on 0.9.5, and is still present in 0.9.6 beta 1 r2674.

Problem description :
I have a score that fits on one page, with only one staff (one instrument).

Using the global style I have made it so that there's plenty of room at the bottom, enough to add at least 4 more lines.

If I try to add a bar, I would expect the new bar to fill the huge blank space at the bottom of the page.
But that's not what happens, mscore creates a new page and puts the bar there.

The "page fill threshold" (not sure if that's what it's called in English, I'm on a French version) is at 100% (not sure what that setting does exactly).

This is on Windows XP SP2. I can post my score file if needed, or try to help as best I can, just ask me for more info.
Thanks