I tried to use the Points in polygon tool in qgis 2.2.0 and it worked fine as long as I used my own points.
When I tried to 'count' the points generated from OSM layers both from dowloaded shapefiles from geofabrik - here I thought the problem is with the projection which is tricky to fix-, but then I downloaded the same points from the OpenLayers plugin with Vector > OpenStreetMap > Dowload data.
The result is the same. I generate the output grid layer but the PNTCNT coulmn is totally empty. Do you have any idea why? I am all new to qgis and these kinds of operations in general, so please explain me what am I doing wrong?!