Created attachment 32624 [details]
If a textbox is within a relatively positioned inline element, the text inside beyond the first character is not drawn correctly until some complete repaint of it is caused (focus change, overflow, etc). If the top/bottom value is enough, nothing will be drawn instead of being only clipped.
Seen in the real world at <http://www.shopthegreatescape.com/> in the "Enter ZIP Code" text box (the top of the text is clipped).
This is a regression from Safari 3.2.3 (tested Safari 4.0.2 and r45758).