Three reasons can explain this:
- This Violations drilldown service only shows 'Added Violations', not fixed ones. Therefore the number you see in this service can be different from the one displayed on a dashboard through the Rules Compliance widget.
- The algorithm detecting new violations is very good but still perfectible. Therefore new violations can sometimes appear only because Sonar did not recognize it already existed.
- You are looking at a period of X days which goes beyond the first analysis made after migration to Sonar 2.5. In this case there can be a discrepancy due to the fact that prior to 2.5, Sonar was not collecting the info necessary to build this service. This issue will disappear as soon as period does not go beyond first analysis.