gtkmm redist. dll (windows) - add_pixlabel -> png-files are not displayed

Question

i just finished a little gtkmm/windows app.

my only problem is that if i use the redist-dll´s of gtkmm the button-images (used with add_pixlabel) are not shown.

there is a button with a red cross (missing).

when i install gtkmm on the computer and run the app without the redist-dll´s in the directory the buttons are shown.

any suggestions`? thanks