Mismatch between R/3 and BW - Accounts 40000 and 50000

hello Experts,

Mismatch between R/3 and BW - Accounts 40000 and 50000

I have found some mismatches between R/3 and BW by means of a query which shows actual information on accounts groups 4 and 5.

The problem is that, thought the query is the same, the performance of today is different than the one on Which i have taken 2 weeks back. This is strange because I am analyzing the period from 12.2006 till 01.2009.

thanks in advance.