SW2004 SP1.0
Try this for me, please. If confirmed, I will send it in.
Start a mate between a couple items and when the floater comes up, ignore it and pick a distance or angle dimension type in the Property Manager area. At that point notice that the existing distance (for example) is highlighted - just what you would expect. However, if you attempt to type in a new value with the num keypad, it doesn't work. The only way to get it to work is to click in the box, which unhighlights the value, rehighlight the current value, and then type in the new.
If you start the mate as above and instead use the floater, both work. If you start the mate as above and instead use the regular numbers, it works.
This is especially frustrating for me as I use the num keypad ALL the time - I hardly ever touch the top numbers. And since I have the view positions macros assigned to the keypad, rather than the number changing, my model goes flying around the screen. Actually, now that I say that, maybe it's Harry Potter coming to visit???
WT