Microsoft released Office 2007 SP2, which I recommend to install and donwload. If you did not install the interm hotfixes which are apart of SP2 you will see a noticeable performance increase.

 

http://www.microsoft.com/downloads/details.aspx?FamilyId=B444BF18-79EA-46C6-8A81-9DB49B4AB6E5&displaylang=en