Unable to manually edit budget values and problems with estimate budget tool

[Paul Roge]

> Also, the estimate budget tool produces a decreasing value for each subsequent entry, probably because it is incorporating blank months in its estimate. For example, I ask gnumeric to calculate my "Groceries" expenses for the rest of the year from a start date of January 1 and I get "1000.00, 900.00, 800.00, 500.00, 0.00, 0.00 ..." 
> 
> It would be nice to just have mean monthly values estimated. Is there a way to do this?
> 

It would also be helpful to know exactly what the "estimate budget" tool is doing. Is there anywhere that explains the math and logic behind it? I have tried running this tool on other lines and the value doesn't seem to always decrease, but isn't constant.

thanks,
Paul