SQL beregne tid (virker men regner forkert)

Hej.

Jeg har en tabel med tids registreringer.

jeg kører denne SQL(forespørgsel) på den.


SELECT Format(b.PanelDate,"dd/mm-yyyy") AS dato, Round(24*Sum((e.PanelDate-b.PanelDate)),2) AS Total, IIf([Total]>8,Round(([Total]-8),2),[Total]=Null) AS Overtid, IIf(Weekday([dato],2)=6 Or Weekday([dato],2)=7,[Total],Null) AS Weekend

FROM Registreringer AS b, Registreringer AS e

WHERE (((e.Paneldate)=(select min(Paneldate) from Registreringer where G=True and PanelDate >b.PanelDate)) AND ((b.K)= True))

GROUP BY Format(b.PanelDate,"dd/mm-yyyy");

Problemet er at den regner forkert.
"Round(24*Sum((e.PanelDate-b.PanelDate)),2) AS Total"

hvis eks.
e.Paneldate="21-01-2012 08:37:43"
b.Paneldate="21-01-2012 11:15:58"
Bliver Total="2,64"

Skulle være Total="2,38"

Nogen der kan gennemskue det ????