Just at the moment I received a mail from Paolo "Bustard" Martella, and he told me that he has released a new version of the benchmark-tool GLExcess.
Here's a snip from his email: I wanted to drop you a line to inform you that GLExcess v1.2 is out now. This release fixes some minor bugs and should prevent lamers from uploading cheated scores once for all. As usual you can grab this patch (which works for v1.1a) at http://www.glexcess.com/files.htm.