We currently migrated from SharePoint 2007 WSS to SharePoint 2010 and our "contribute" permissions seems to be acting "not as described". When we create a new site, we grant everyone "contribute" acess, BUT all users are not only able to edit lists and libraries, but they are able to edit the main page of the site (web parts, text...). What we've done is grant users "read only" access to the main site page and then grant "contribute" access to lists and libraries.

Does anyone know why this may be happending? We have the work around, but would rather keep the permissions simple by just granting contribute access to users when the site is created.