Changing the headers in sidebar filters

may be a silly question
I removed in the filter area in the web direct layouts the possibility to filter projects (doesn't) need projects.
Now I want to change the header from (Title, Project Status) to Titel, Status.
But after a double click on the tab control setup all is grey and i cannot change the tabs ?
Whats going wrong ?
best regards
Juergen
I removed in the filter area in the web direct layouts the possibility to filter projects (doesn't) need projects.
Now I want to change the header from (Title, Project Status) to Titel, Status.
But after a double click on the tab control setup all is grey and i cannot change the tabs ?
Whats going wrong ?
best regards
Juergen