Okay, this one gets me all the time. I grant a role the ability to edit certain nodes and when they log in and try to edit a page, there's no edit tab!

Chances are that if you've tried everything else, you need to grant that role permission to use whichever input type you've set for that node or set of nodes. To do so:

1. Edit your node and check what input type it is set to use
2. Go to Site Configuration > Input Formats and then make sure that the corresponding input type is configured to allow the role to use that type.

Sometimes, in my case, a node will get set to use "Full HTML," which is never really a great idea, and in doing so, prevents most roles from being able to use that type. As a result, even if a role has permission to edit a node, they won't be able to see the edit tab because they don't have permission to use the Full HTML filter :( This applies to Drupal 5 and 6.

If someone has time, perhaps they should work in some kind of warning to show up in situations like that -- perhaps just for admins letting them know that such a situation could arise based on their input format / permissions settings.

Hopefully that helps some of you out there!