After performing an update from CE 3.2r to CE 3.3g on a testing system I have the same problem. Before updating all was fine, now the special chars as "ü" or "ß" are shown as the respective html entities inside of the wiki dashlets. But if I'm watching the common wiki entries, they are shown as expected.
Now I've looked at the html code with the TinyMCE - they are saved as shown: as html entities :?:
That shouldn't be a problem, but the dashlets don't interprete them…
At the productive 3.2r machine the chars are stored as html entities too, but there share has no problems with that.