I have a number of bodies disappear but I can still retrieve items from them. Also have seen animals fall from the sky right in front of me.

I've had bodies disappear on me since 1.1 but only when I be-head someone.

I've seen this too , sometimes when I shoot someone and turn to kill someone else , the first guy disappears . If I find the right spot on the floor , I can sometimes drag them back up to loot them .
I had a Hargraven fall out of the sky today , and last month I was climbing a mountain and saw something rocketing towards me . I ducked aside and a horse hit a rock right next to me then shot straight up into the air . Very odd .
Today I was doing the get the Horn of Jorgen Windcaller quest . While in the dungeon I killed a restless draugr , after it died it got back up and stood in place with its arms straight out , rocking back and forth . I could not knock it over and every time I shot it with my paralyze bow the screen said " restless draugr resisted paralyze " . . It was clearly dead though because I could loot it's body .

I had a similar issue, the corpse were being svcked into the ground. If I recall correctly, I had this happen with only humanoids, no undead, etc. Usually, If I can guess correctly where the body should be then I most likely could loot it if I wanted to, but this for me did not occur often.

Yeah this has been happening to me since release, I don't know why, but it doesn't happen so frequently; also, when it does happen it's when I'm fighting like something cool, and I miss out on what's on it :c