Change in points?

[Phoenix_sof]

Hi.. I am not sure whether this is a bug.. Just wanted to clarify..

As on 12 June 2009, I had 24.4 points in my account (Username: zyxw).
Today (23 June 2009) i solved a problem (code: DANGER), after which i have 23.7 points

How does the points change (decrease), when the number of problems solved seem correct ?
Is there any change in ranking system ?

PS: I'll upload the screenshots if needed.

[Robert_Gerbicz]

From spoj:

Please note that the formulae used for calculating the scores are currently evolving. At present points are awarded to each user as follows:
    * for solving classical problem p: 80/(40+number_of_people_who_have_solved p) points
* for a top score in any challenge: 3 points,
* for any lower score in a challenge: (user's_score relative_to_the top_score) points.

[Phoenix_sof]

Hmmm.. If this is legal, then ok
Sorry for the post..