BB/100 , BB/hour calculation

Hi,
not an imortant question, but i´m curious....
At my session yesterday (sorted with "session by time") i have a positive "amount won", a negative value at BB/100 and BB/hour and a positive $/hour value. How is that possible? How can i loose f. e. 3BB/100 hands but win 15$ in the overall session? I played two different limits, but still have no explanation for that
thx in advance
edit: sry, i think i understand this now. This happens when i´m loosing some BB at the lower limit and win at the higher limit, so my BBs are still negative, but my absolute winnig might be positive...
not an imortant question, but i´m curious....
At my session yesterday (sorted with "session by time") i have a positive "amount won", a negative value at BB/100 and BB/hour and a positive $/hour value. How is that possible? How can i loose f. e. 3BB/100 hands but win 15$ in the overall session? I played two different limits, but still have no explanation for that

thx in advance
edit: sry, i think i understand this now. This happens when i´m loosing some BB at the lower limit and win at the higher limit, so my BBs are still negative, but my absolute winnig might be positive...