[Bug 6006] incorrect paint of invisible buttons

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=6006

------- Additional Comments From [e-mail]  2007-01-03 21:53 -------
Created an attachment (id=5187)
 --> (http://bugs.winehq.org/attachment.cgi?id=5187&action=view)
reproduction.c

Finally, I think this is a true reproduction of the problem unlike the previous
attempts.
Comparing the text output between Windows and Wine shows that wine doesn't send
a WM_ERASEBKGND message which leads to the button not going away when made
invisible.