Info:
After some time (maybe quite long time), I can see the entry in the table. I removed the entry from the table, then went to admin tool to delete the theme from db. But when I started personas, I could still see the deleted theme on UI. When I tried to edit it (in order to remove it from UI), the edit panel went away again. Some thing went crazily with theme handling.
(by the way, why cannot I delete the them from admin tool?, I guess it should be the Strong way to remove themes, right? Normally, we just need to remove them from UI.)
Dong