Interesting havent actually checked to see if that occurs in my reports. If I had to assume potentially the problem comes with the aggregation of data over time?
Miron is correct.
Statistics are summarized over the time, it will lead your reports to lose accuracy as data is averaged.
You can minimized this issue you noticed by increasing the data retention in your settings:
Start > All Programs > Solawinds Orion > System Manager
File > Orion Network Performance Monitor Settings...
In the database tab, edit the Statistics Summarization settings for the Detailed, Hourly and Daily statistics.
Beware that it will increase your database disk space requirements if you keep e.g. detailed stats for 180 days.