Kiran,
I fee that you must investigate through table CDHDR. Run Tcode SE16 --> Give value CDHDR --> Enter.
Here input values as under ( OBJECTCLAS, OBJECTID, USERNAME) and Execute.
In the output, you observe the values of fields TCODE, UDATE. You will come to know whether these changes are happening through IE02 or some other Tcode.
Also you should try without giving the USERNAME also. In this case you will get the lines of both normal changes and surprise change also in the output, where you are likely to find out what is happening.
In a similar way, you can investigate through table CDPOS also.
Jogeswara Rao K