When I look through the "Review Suggested Edits" tab, there are always buttons for Approve/Reject/Improve. These buttons appear unless I've already voted to Approve/Reject the suggested edit.
After voting to Approve/Reject an edit, a notice appears which I usually ignore. It often reads either "Waiting on 1 more vote" or "Edit has already been approved/rejected". However, it sometimes reads
Out of votes - you may only vote 40 times a day.
When this is the case, perhaps instead the system should:
Place a banner at the top that reads something like:
These edits were suggested by users who have not yet earned full edit privileges. Approve edits you know are correct; reject those you know are wrong. Leave ambiguous edits for other users to judge. You may also view suggested edit stats.
You are out of votes for today; you may only vote 40 times a day.
Disable or remove the Approve/Reject buttons after each suggested edit.
It sometimes takes me a few times to realize that my efforts are wasted. Granted, this is in part because I don't take the time to read the notice, but I still think adding this bit of functionality would be a sociable thing to do.
This goes as well for the "edit(n)" notices on questions/answers that are viewed on the site rather than through this tab.