st: scalar troubles?

[Edwin Leuven <e.leuven@uva.nl>]

dear all,

running one of my ado's i get the following table

-----------------------------------------------------------------
                        |         Mean                   % reduct
    Variable     Sample |  Treated   Controls   % bias     |bias|
------------------------+----------------------------------------
       Ltaal  Unmatched |        0   -.547782    118.0
                Matched |-.7002011  -.6988459     -0.3       99.8
-----------------------------------------------------------------

the unmatched mean among the treated should not be zero however

the piece of code that calculates it is simply

        qui sum `v' if `treated'==1

which gives, when i remove the -qui-, the following

    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
       Ltaal |       296   -.7002011    .4792868  -2.157421    .846165

then i do this

        scalar m1 = r(mean)
        scalar v1 = r(Var)

and adding this as a check:

        di m1

gives

0

!!

if i change the name of the scalar to m1x, everything works fine, ie the 
 0 becomes -.7002011

i am baffled...

does anyone know what i am doing wrong?

thanks a lot, edwin

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