I installed OneCare a few days ago with printer sharing, and could scarcely use Word (it was so slow) until I discovered that that PS was the problem and disabled it. Now PowerPoint can't play a movie clip without stuttering and multiple audio drop-outs. Is this also the fault of OneCare? Why aren't you telling new customers about these issues before they buy?
I'll add to Jim's reply by addressing this part of your post: "Why aren't you telling new customers about these issues before they buy?"
Because what you are experiencing is not expected behavior, nor has it been widely reported. In fact, I don't recall reading of either problem *ever* before in these forums.
Please do contact OneCare support.
-steve Microsoft MVP Windows Live / Windows Live OneCare & Live Mesh Forum Moderator