I can't reproduce this. Are you able to compile QMapSahck on your own to analyze the root cause? If you can I can point you to the code lines to play with.
I compiled QMapShack from the source. And now the icons are there!
This is really strange. See, all those buttons are action object defined in IMainWindow.ui. They have been all created by the same dialog in QT Designer. That's why it is strange that some icons are shown and some are not.
Maybe it's a good idea to ask the maintainer of the Ubuntu package if missing icons are reproducible. Maybe the package has to be recompiled.