I found that if I un-attach the toolbar that is at left (the one which has the normal arrow, the arrow to edit nodes, etc (the only one vertical)), the problems dissapears.
I assume that the problem is that this bar cannot hide buttons automatically when they doesn't fit the screen.
I found that if I un-attach the toolbar that is at left (the one which has the normal arrow, the arrow to edit nodes, etc (the only one vertical)), the problems dissapears.
I assume that the problem is that this bar cannot hide buttons automatically when they doesn't fit the screen.