http://bugs.winehq.org/show_bug.cgi?id=12813
--- Comment #3 from James Hawkins truiken@gmail.com 2008-05-03 01:28:25 --- After some intense debugging with the help of Dmitry, we've figured out that the MsiHiddenWindow window should only be created when needed by the msi dialog code. As it stands, we're creating this window when msi is loaded. This particular installer calls ExitThread which destroys the MsiHiddenWindow, causing the rest of the dialog problems. The solution is to load the hidden window from the dialog code.