If some dll's were missing, your users wouldn't be able to run your program
Oh..I know that, but anyway you get me correct..I suspect one of the non-essentials.

My program runs with the collaboration with another program(a script-like UI application) which is also written with Qt. Maybe it induces to problematic case.
Or maybe I should check some environment variables, ha?

PS: Sorry but the code package isn't available right now..