Group calculation not working

Hello Antoine
excuse me for postng a question at this point/moment of the world cup.
On my installation everything works fine – except of one thing:
The group calculation doesn’t work – no match count, no points, no changes after first match and first calculation. Same behavoiur on groups page and on group widget…
Would be great if you have time to answer and of course if you have any idea about this …
Thank you and best regards
maybor