I've seen this before, and I think it's because at least part of the dimension has been associated to an actual 2d or 3d point in the drawing plane in AutoCAD. I could be wrong, though. Try selecting all (ctrl-A), typing dre (dimreassociate, dre launches it for me, but that may be something I customized... just launch the dimension re- associate command), then holding down the enter key. It's been a while, but that may fix the problem. Either that, or select all, then in the properties window, select the various items, in turn, that are dimensions (ie: linear dimensions, etc..), then change the properties of the entire group to "UnAssociated". That should clear the problem right up. If this is still not working, then you may need to write your own VBA-Sub to select all dimensions, and set them all to be "Unassociated". If you are feeling really adventurous, try writing a sub that lets you select some objects, then pauses execution, then you can examine that object in the Watch Window; compare a dimension that moves properly to one that you know will not move properly (an example of a dimension that will not move properly can be obtained when next you have this problem; just choose "undo" until before the move. Then move it again just to make sure the problem still exists (if the problem goes away once you undo the move, then make the move again, then problem solved :) ). If the problem still exists, undo to before the move, then examine, in VBA, the properties of the afflicted dimension and compare them to a properly working dimension. If you can discern the difference, you can probably set that property directly using a VBA-Sub. Just write something that will select all objects that are dimensions, and then change that property in all of them. Or, find someone who knows what the hades all that gibberish means and ask them to do it. I could do it myself if you cared to email me an example of this problem occurring (a .dwg where the problem occurs - if I have an example, I can do more, as long as I have that version of AutoCAD at home, which I might).
-Clayton