Hi,
PowerDirector 7 will NOT remove DVD Suite. It will however replace specific programs with an upgraded version. In your case it will be PhotoNow and you will need to agree to this as PowerDirector 7 and PhotoNow are integrated, rely on each other at some point.
DVD Suite contains a version (an Express version) of PowerDirector and this will remain on your PC and be accessible.
PowerDirector 7 installs and DVD Suite remains. Use PD7.
Hope that helps.
Dafydd