I kind of think I know what you're describing. It's called shadow "banding" or "striping". You get it on objects like rocks etc?
Go to SkyrimPrefs.ini in Documents/My Games/Skyrim
Change the line ShadowBiasScale=
To 1.000
I think it's default is 0.3000
See if that helps.
It's NOT that. That is one feature that shows up a lot, but it's a lot more. Like I said, shadows go CRAZY. They're everywhere. I think it actually started off worse when I first updated but it's still terrible and unplayable. They flicker and they dissapear and they go places they shouldn't be, and they sometimes move with my camera as if the sun were locked to move with it, and in 3rd person, depending on the angle I'm looking at, there will be a big square off to my left of shadowed area and then a most of the screen will have no shadow, but then not always, it's really all over the place, it's more than a simple banding issue or a blocky shadows issue.