>This error can be reproduced outside or PEMEditor, once you have done Modify Class:
>

ASelObj(aObjects,1)
>oObject = aObjects(1)
>Amembers( laLines, oObject, 3 )

I open a class

MODIFY CLASS myclass OF c:\vfp9\myclasslib.vcx

Then in the command window I run the above code you posted.
I do not get any error. So in my case with my class it is not reproducible in VFP9 sp2.