I have several dwgs that some how got all or almost all of the dimensions in the dwg exploded is ther a way in ACADM 2008 to re-associate those dimensions?

This happened to me today too.  'Twas the first time this has ever happened to me in Autocad.  Resolved by the DimAssoc variable. Accepts the following values:
0 Creates "exploded" dimensions (pre-AutoCAD v2.5 style).1 Creates "non-associative" dimensions (AutoCAD v2.5 - 2000i style)2 Creates "associative" dimensions (the default value).I used '2'.

You can try the DIMREASSOCIATE command.