Key Framing Duplicated Objects...

I’ve run into a problem with 2.56a regarding key frames and trying to key frame an object that has been duped. After making a duplicate of an object, I can’t generate key frames for either object without the key frames being assigned to both. The duplicate is a full dup, they are not link duplicated. The objects show as completely different objects in the curve editor and elsewhere but still end up with duplicated key frames. This doesn’t seem to occur in 2.49. Anyone have any idea what I may be doing wrong?
Another immediately related issue concerns the channels in the curve editor and dope sheet. They appear as you generate key frames for an object but apparently cannot be deleted thereafter, even after all key frames have been deleted. Is this normal?