Thanks for your time! I have tried both the portable version that this site links in the download section, as well as yours, and I am having the same issues with both. I did not make any changes (I still have to understand how to arrange them for the Italian layout, but that's another point) and I notice the alt+ctrl problem when pressing indifferently LAlt or RAlt.

Actually Excel uses the comma as decimal separator. Is this an option that can be set somewhere?

Yes, shortcuts work, except for the ones with alt+ctrl, and as you say for the ones where I have to use a dead key.

Okay, let's see. I'm using PKL all the time on several machines. The one I'm on now has Windows 7. No MS Office, but I'll try in LibreOffice Writer. Testing the Ctrl+Alt shortcuts there (Ctrl+Alt+Up to move paragraph, Ctrl+Alt+Shift+V to paste unformatted) works fine with PKL for me! This includes using the Extend mappings (Caps+A+T+U to move paragraph).

A new keyboard most likely won't help; if you're in doubt you could try borrowing someone's keyboard but I doubt it'll matter. Seems this is a problem with some system settings you have?

In Excel, there may be an option for decimal separator. However, most likely it uses your system's decimal separator set in the "Region..." control panel.

For the dead key letters, you can have them on AltGr mappings and then the shortcuts using them might work.

By the way, here's how I recommend to remap Colemak for Italian:

For PKL, there's a layout.ini file inside the layout folder you're using; there you can actually just paste in the letters you need in the right mapping positions. Make sure you make a backup first. ;)

[edit:] Actually, I decided to be extra nice: I've made you an Italian Colemak[eD] PKL layout! If you download my latest PKL files from my PKL sig topic, there's now a 'colemak-eD-It_ISO' layout in there that should do the job. Hope it'll help you and/or someone else! It's not using a Wide ergo mod, so keep that in mind. Should you want the AngleWide mod we'll need to paste the relevant characters into the right lines of a copy of the Wide Norwegian layout in my PKL layout folder...

Glad it works for you! :)

Yes, sometimes you need to choose between the full functionality of a key and the Extend layer. For me it was like that with the Tab key; that needs to be unmapped for me.

If you have a "non-wide" pkl.ini and a non-wide layout like the Cmk[eD]-It I gave you, you can try the Extend mode! Press Caps and U for the Up key for instance, and Caps+A+T+U is Ctrl+Alt+Up (see my sig topic for more). Check whether that works for your shortcuts; it does for me. I think the pkl.ini in my folder is based on a "wide" setup so you'll have to copy-paste the "non-wide" pkl.ini to be your pkl.ini first.