>

>OPEN DATABASE S:\praktyk\data2005.dbc
>SET DATABASE TO DATA2005
>
>nTel1	= ADATABASES(laGroep1)
>
>?lagroep1(1,1)    && gives data2005
>
>CLOSE DATABASES
>
>nTel1	= ADATABASES(laGroep1)
>
>?lagroep1(1,1)    && give data2005
>

>
>Sorry, i forgot to place the extra command adatabases with transporting the question to this forum
>it still gives the same result, even when i rerun the adatabases command

Viv hit the nail, I think. The array is nor redimensioned if there are no open databases. Try

OPEN DATABASE S:\rap\data2005.dbc
SET DATABASE TO DATA2005

nTel1  = ADATABASES(laGroep1)

?lagroep1(1,1)    && gives data2005

CLOSE DATABASES 

Release lagroep1
Dimension lagroep1(1)
nTel1  = ADATABASES(laGroep1)     

?lagroep1(1,1)

I agree that this behavior is scary, and may lead to unexpected/wrong results.