Minusing a negative in an excel formula

Hey guys,

I am trying to build a spread sheet to keep track of my hours worked and to keep a record of wether I am up or down on hours over a given month. The problem I have is if I start a month with negative hours (hours owed to the company) my formula will not work correctly. My formula is this '=B41-(C6+(COUNT(B9:B39)*8))'

B41 is the hours that I have worked in the month minus C6 which is my time owed/time off plus the next bit of the formula counts all my hour inputs and works out what time I theoritically should of worked in that month.

If C6 is say -2.00 at the start of the month, even before I have input any data the formula is coming out with a positive 2.00 something to do with minusing a negative I think but I can't get my head round it. Any help will be muchly appreciated!