Press M to open the map. Then click anywhere. Now you have the same angle.
If you do want to play with the right graphics, I believe it works better in 640x480, but you tell me.
The straight graphics/cluedo mode? I believe in in early versions there was no 'high-res' keeperfx, so if the problem is indeed only in high-res that could be it. But even if not, I doubt it is a recent problem, it has been like this for years.
OK, I just tried it for you, and yes, in 640x480x32 this screen mode works well. It just looks really bad in high-res.
I don't have a solution for you. This is the first time I hear of this problem, and I don't have a widescreen monitor.