Formulas for calculating timesheet

Hello,

Sorry to be such a pain, but I've extended my original timesheet to include annual leave, personal leave and public holidays. What my problem is that when someone is away for the day for either public, personal or annual leave in the the o/t time it calculates itself to read 6. I'm not sure how to fix this. Can someone have a look at the timesheet I've attached and advise me on how to fix this problem.

Many thanks,
Val C

A big THANK YOU to everyone's help.