Obvlion use the Gamebryo engine, Skyrim is using Bethesda's proprietary Creation engine. This is most likely why there are so many issues, new game engine new problems.
I am using the nVidia beta drivers, but still have random crashes and frame rate drops for no reason.
It was already said a couple times, but the engine isn't really different. It's a modified FO3 engine renamed to 'creation'
It is still gamebryo at it's core. Bethesda built Morrowind around a dx8 middleware called netimmerse. gamebryo was the dx9 version of netimmerse. Bethesda licensed it in 2006 for Oblivion, updated their Morrowind SDK to use the new features, wrote some of their own shaders, and integrated other engines with it like facegen, speedtree, and havoc. They never licensed any other versions of gamebryo except the 2006 one in favoring of making their own modifications and enhancements seen in FO3. I am guessing they have made enough modifications to call it their own, which they did (creation). In 2009 there was an interview that said they're going to use it for future products because they've built all their tools around it and their staff is so familiar with it. The performance quirks people like to blame on the gamebryo engine are not the engine's fault. It's the programmers. And mostly due to its open world nature. Other games used gamebryo without as many bugs and quirks (and they had ladders too).