I tried to solve the following issue by myself but without success. On the one hand I have a raster file which is the result of the processing "shapes to grid" tool. On the other hand I have a boundary vector file. Now I wanted to use the zonal statistic tool via processing toolbox. But the result isnt correct. The mean value is not what it should be. The metadata (grid file proberties) shows me the correct mean value. The crazy thing is, when I convert the raster into a shape file again and then converting this shape into a raster file once more the zonal statistics tool works fine.
Could please anyone check this for me? I'm using QGIS 2.2. The files are here (EPSG 25833): Link