MS 2007, 2010 in EPM issues.

1. We have upgraded from MS 2007 to MS 2010 in users pcs. Some complex reports which runs faster in users with MS 2007 is running slower in MS 2010. Has people noticed this kind of issues?If so what is the solution? 2. Also in EPM 10NW,if there any excel or MS version installed in server? How to check it. If so has the server version and end user installed MS version needs to be same for the reports to be faster. For example if EPM server is installed with MS 2007 , do we need the MS 2007 version only to be installed and used by the users..for the reports to be faster. Appreciate inputs..