From the US boards:
QuoteSince this has come up so often, I guess I will leak a feature of Issue 8:
You can change your title at any of the following levels:
15, 25, 35, and 45
At 50 you can change your title at any time.
You need to visit a trainer still to change your title and they "don't stack" (in other words, if you don't use your level 35 change, you don't have two changes when you hit level 45).
There is no Influence or Infamy cost associated with this.
So you're not stuck being Magnificent and yet Indescribable for ever. Just for the next ten levels. :)