Ah, found the bug report in mantis and answered a question or two of mine. You have had versions back to 1.2 (and before?) and it looks like you do run a pretty high resolution from the screen shots you sent Maurizio.
BTW, about the .NET; check in your control panel. The version installed for several releases has been 3.5sp1. It’d be -highly- unusual for windows to allow a step back from that (assuming it installed correctly for you). I remember the fits I had trying to dial back (and keep) directX for a game I play. Control panel will tell you what ver is installed.