Slow ms access forms in ms office 2007 when converted from office 2003

When an application developed for office 2003 is opened in access 2007
you might experience some slow behavior in controls that compute sum.
there is a hotfix for that.
steps:
make sure you install office service pack 1.
(be carefull when choising the right language, and conform it. It is a
kind of tricky)
http://www.microsoft.com/downloads/details.aspx?displaylang=nl&FamilyID=9ec51594-992c-4165-a997-25da01f388f5

install hotfix pack
(send a request and the fix will be emailed)
http://support.microsoft.com/kb/956054

now it should work!