Frustration with permissions

I have a 5-state revisioning workflow set up for 3 user roles.

Role 1 can always make edits. Roles 2 and 3 are meant to be able to edit pages when the page is in workflow states 2 and 4 respectively, however they cannot. The permissions in "Access Control" on the workflow editing page are set appropriately, so the problem must be somewhere else, but I can't see it.

edit: I have since discovered that only the original creator of the page can make edits.

Also, users 1,2 and 3 all have permission to revert revisions in the node module, but only the administrator actually has that option displayed can do this. Presuably that is linked to the fact that they are the only user with 'adminsiter nodes' permission, but I don't see why it should be that way.

If any one can help that would be great. If I find a solution I will post it here.