does it happen to every object you move? Try creating a new empty file, putting a rectangle in it and moving it: does the error appear?
If it keeps popping up, you may want to delete your AIPREFS file. If you don't know what it is, how to find it and how to delete it - search the forum for the word aiprefs.
Ctrl-A is the key. You didn't mention it in your previous post.
Unzoom all the way till you see ALL the board space available (surrounded by some gray cosmic emptyness). Do Ctrl-A and see where the bounding box of the selection is. Chances are, there're some objects out of the Artboard that you don't see while working at the page scale. Delete these object and life will become much easier :)