http://bugs.winehq.org/show_bug.cgi?id=9444
--- Comment #21 from Hans Leidekker hans@meelstraat.net 2011-10-31 06:20:02 CDT --- (In reply to comment #19) ...
but with +msi turned on, the log continues, and ends with
trace:msi:MSI_ProcessMessage (nil) (nil) (nil) 0 8 L"1: You must simulate a Windows reboot to complete the installation. Click Yes to do this now or No if you want to do this later 2: " trace:msi:msiobj_release object 0x16cf18 destroyed trace:msi:MSIHiddenWindowProc 2 (nil) trace:msi:MSIHiddenWindowProc 130 (nil)
so now it's a UI problem?
Looks like it, the MSI_ProcessMessage trace reveals that this installer has not installed a UI handler, so it's probably msi's responsibility to show a dialog here.