Meanwhile it's over 1250. There must be something wrong with the Elo-rating. Perhaps some rounding errors.

If you check the linked Wikipedia page, you will find a formular that says the average winning chance of somebody with 1200 rating against somebody with 400 rating lies at E = 1000/(1000+1) = 99.9 %. Of course Cultris system works a little bit differently, but I am sure chances would be above 90 % in this case.