I am trying to use the new heatmap plugin to create a heatmap from about 10k points. When I enter the parameters and start the process , QGIS becomes unresponsive. I don't get a progress bar or a dialog. If I let it be, it generates the heatmap after an hour or so. On the same system, GRASS's v.kernel creates the heatmap in under a minute. I tried with a few different parameters and reducing number of points but it isn't much better. What am I doing wrong? Have others seen such behavior? I am using QGIS 1.8 on Windows 7.
The data I am trying to work with is at http://data.london.gov.uk/datastore/package/policeuk-crime-data