Difference in intraday and eod data.

#1
I use data file generated by RK Global diet ODIN Intraday charts(supposed to be tick data).
When I Sum up the volume data it is always substantially more than what is shown in EOD data or Total Traded Quantity (TTQ).

E.g.

Sum of volume from chart data for HDIL today i.e. 13 May 2010 is 7631138
where as TTQ is 7160805 which is shown in diet odin software marketwatch and is same as nse bhavcopy and website data.

Can anyone tell me why this difference in numbers.