Are you still supporting this UI by chance? It no longer loads properly.
Here is a fix for anyone that needs to make it work, but it isn't the best fix in the world
1) Copy EQUI_Templates.xml from the default skin to the folder you have Miettte in.
2) Edit EQUI_Templates.xml and comment out or delete all the QMarkBox marks.
3) Save the modified file and load the skin.
To comment out the box, add <!-- in front of <QMarkBox> anf add --> at the end of </QMarkBox>