Cross Tab - Embedded Summary - CR2011

Hi all

I'm a newbie to Crystal so am sure that I am missing something glaringly obvious.

I have a crosstab that shows a persons activity for each given day that then summarises by week, month etc..

Within the row totals I have some crisitcal information. I have then added an embedded summary withing the totals section in a bid to identify the number of hours a person is spending in the office per day

Date Contracted Hours Shift Start Shift End In Office Hrs

01/10/2012 07:15:00 08:00:00 17:00:00 09:00:00

02/10/2012 07:15:00 08:00:00 16:30:00 09:00:00 <- this should be 08:30:00 not 09:00:00

The shift start time = minimum ({@task_start_time_seconds})

The shift end time = maximum ({@task_end_time_seconds})

In office Hrs - Embedded Summary = maximum ({@task_end_time_seconds}) - minimum ({@task_start_time_seconds})

What am I doing wrong. Is it because I am using an embbeded summary incorrectly?. How can I correctly calculate the in office hours in the totals section of the cross tab.

many thanks

an incredibly frustrated Stewart