OK. This one is silly.
In the tag admin screen, where you have a list of all your tags. Any tag that is greater than 10 characters only shows the first 10 characters and then you get a ...
So if you have a tag "Some tag name", it would show in the list as "Some tag n..." -- silly.
There's no reason for this -- or at least not at such a small limit.
Please fix this.
Silly.