@Rob1n: Thank you! You were perfectly right.

I just had a quick look at the directory names at first, and though that "mbarcode" was used to indicate where some shared files ended up on the hard drive after install. It seems it doesn't do that at all, and that the dpkg builder needs the folder name to be the same as the package.

Again, thanks! Hopefully the update will fix the missing shortcut in a few minutes.

For those wondering, the first update of mbarcode-core that fixes the problem has version number 1.0.2-6. This version is forced by minimum by mbarcode 1.0.3-1.