Text scale and origin in 2.5

i tried to and did convert some added text in a script

but i also need to change the origin and set it in the middle of the new object

but always get an error on this new center

bpy.ops.object.scale_apply()

bpy.ops.object.scale_clear()

here do i need theses 2 line to clear the scale or only one?

bpy.ops.object.convert( target=‘MESH’, keep_original=False)
bpy.ops.object.origin_set(type=‘GEOMETRY_ORIGIN’)

this last line on origin is not workking

can someone correct this line so it can work cause i need to re lcoate this object function of the center of the object and not be on the left or the text converted to mesh!

appreciate any help Thanks