Error LINEST_M with zero intercept?

[#1]

Given the following set of numbers

load * inline
[a,b
1,2
2,4];

returns QlikView  the following values for the slope of the linear regression

linest_m(b,a) = 2          - Korrekt

For the slope given the intercept 0 it rerturns:

linest_m(b,a,0)  = 2.8   - which is inkorrekt.

Is this an Error? I couldn't figure out what QlikView computes in this case.

Also on non trivial examples (many data points, "well distributed") QlikView gives different results than Excel for the slope when the intercept is zero.

Any help is welcome.