unable to make intaglio's commands "scale" & "transform" works on applescript

everytime i try to run thoses 2 simples scripts:

1/using command SCALE

tell application "Intaglio "
activate
make new path at beginning of document id 1 with properties {segments:{arc, {1.0, 0.0, 0.0, 0.299578070641, 0.0, 215.029525756836}, {227.5, 425.5}, 118.5, 0.0, 6.283185482025, true, close path}}
scale {graphic id 1 of document id 1} by {0.5, 0.5} about {250.010314941406, 223.561584472656}

end tell

or 2/using command TRANSFORM
tell application “Intaglio”
activate
make new path at beginning of document id 1 with properties {segments:{arc, {1.0, 0.0, 0.0, 0.299578070641, 0.0, 215.029525756836}, {227.5, 425.5}, 118.5, 0.0, 6.283185482025, true, close path}}
transform {graphic id 1 of document id 1} by {-1.0, 0.0, 0.0, 1.0, 587.510375976562, 0.0}

end tell

i get the permanent message “this value in not adapted to the properties” and the script stops!

why theses 2 intaglio’s commands don’t work and react with this error message ?

what should be the -value adapted to the properties-?

andre