The nullLabel error has been solved and the component works some way. I think something is not yet OK with filtering and there seems to be a difference how it works depending on whether there is only one filter or 4 filters.
The one filter page works pretty reliable, the 4 filter pages works rather erratically.
1. The filter options very often are very difficult to select. They just fly away and the filter reverts to the default value.
2. When you select a filter option, the filtering is done, but then the process seems to go on endlessly refreshing the screen continuously. You need to stop the processing with the browser stop button. This happens with IE9, FF and Chrome.
3. Even if set "Submit on change" in the filters attribute, meaning to me that the filtering is done automatically without klicking the search button, same as in Standard Joomla, this process seems to work quite randomly, sometimes it filters automatically, sometimes you have to klick the search button.
4. In my opinion filter labelling could be ditched. I have never seen labelled filters anywhere as usually their meaning is described by the default value inside the filter box.
