Hello again, it's me with yet another issue with Inkscape 0.43, this time the clipboard.
I don't seem to be able to copy elements from one window to another. I do remember, however that this was possible to do with Inkscape 0.42 and 0.41; on 0.43, however I'm unable. Whenever I copy a group, shape or anythin of the sort to the clipboard, change the window and try to paste it, I get a message that the clipboard is empty. I assume that each window has, then its own clipboard, as I can paste stuff copied from a window within that same window; either that, or two different Inkscape will spawn two copies of the program and thus two clipboards. I still have to see how does opening a new .svg from the "Open" dialog within the application reacts instead of launching Inkscape from the MIME association in the filemanager (GNOME and Nautilus in my case)...
Little, tiny update: Indeed. Apparently when opening an .svg from the filemanager other than the one you are alrady working with, it will spawn a new copy of Inkscape, and thus a new clipboard, where as when opening another .svg from within Inkscape, the two windows will share the same clipboard... Still, I don't remember this behavior with 0.42 and 0.41.
I know I have already answered my original question, but still, why is this the case? And (I know there's going to be people who won't agree with me on this) this is actually a great thing! As you can work on several projects at the same time several files each with several instances of the program opened, and they will not interfere with each other. Excellent!