Confused about "future" figure, take into account scheduled payments??

[Ash Powell]

Hey all

I am a bit confused about how the system predicts its "future" figure
for a given account.

For example; I have an insurance account set up to be drawn upon for
CTP, comprehensive car and home insurance.
I have these withdrawls scheduled for the dates they occur. (various
dates through the year, some monthly, some anually)

I have divided these large bills into small fortnightly deposits which
are scheduled to go into this account from my main savings account.

The intent being that I pay small, fortnightly amounts and then when it
comes time for a large bill the full amount is there, ready to be drawn
out.

The "future" figure on this account is always in the red by large
amounts because it seemingly fails to see that the large bills are often
not due for a year or so.

The account does not CURRENTLY have enough funds to service that debt
but it WILL when the time comes for that scheduled payment, due to the
accrual of the scheduled payments. 

I guess what im asking is why does it reflect future, scheduled debts as
being current?
Why doesnt it also take into account the scheduled payments if it wants
to predict the future??

Ash