It actually does show up but it's completely black wihout controls. And this time it really minimizes after 100 ms.
And the solution was... stupid. I still use the method imported from coredll.dll, but just before I minimize the app I switch the window from "Maximized" to "Normal" and switch the MinimizeBox on. Then, when my "minize" fires, it is equal to tapping the OK button in the top right corner (They call it SmartMinimize I think). It's unnoticeable to normal user.
OFC, you can include this in the ROM if only you think the app deserves it. Sorry for not being quick enough to have this version ready before releasing of your 1.0.1.
Ad.1: Yes, you're right. I noticed that the installer doesn't uninstall the previous version if the cabinet name is different... Will be done in next release.
Ad.2: didn't think about that. Not sure how shoud I do it, but I'll look at it.