>Its just this piece of code. I need to concatenate some field names into a string, so the actual code is :
>
>

		lTempFields=""
>		FOR i=1 TO lnCampos
>			IF ASCAN(TblFields, UPPER(This.iaData[i, 1]))>0
>				zz=ALLTRIM(UPPER(This.iaData[i, 1]))+","
>					
>					lTempFields=lTempFields+zz
>			ENDIF
>		ENDFOR

>
>Tblfields has a =AFIELDS() of my table, so Im getting all the strings in ladata wich have a corresponding field in the table


If you run this code as a one simple program (right after you did clear all), will it work?

I think something else is affecting this (say, are you running this with timers running)?

For now, try running same or similar code in a new VFP instance.