excel 2010 very slow to open/save workbook

I have installed excel 2010. My workbook (created with office 2007), is slow to open and save. Approx 30secs to as long as a minute.
I have researched as much as poss, but no solutions. Tried changing the DDE settings, Have done a repair to the program. The workbook is very small (1.9mb), has no macros, very basic data. (some check boxes)
Any ideas what else I might do to speed this up?
Running XP pro
thanks in advance
Dave