http://bugs.winehq.org/show_bug.cgi?id=16183
--- Comment #9 from markk@clara.co.uk 2010-04-17 06:47:39 --- Testing with Wine 1.1.42, this problem is still present but less severe.
The initial pop-up display is still blank, but as you move the mouse wheel down to increase the pop-up size, each increment causes the text to either appear as it should, or the pop-up to be blank. (In other words, the text is not always overwritten any more.)
I'm not sure what determines whether the pop-up at a given size is blank or not, but the first movement of the mouse wheel does seem to consistently cause the text to appear.