[Closed] Help with Curve Control

Hi!, I did this script to add a curve control on a custom attribute definition, and then add this definition to any object.
Basically what the scrip do, is take a cuve profile, a cycle and a multiplier, and applies a procedural cycle animation, using the curve profile as a guide.
everything seems to work fine, but when I leave modify mode, and enter again, the curve is resetted. I have tried almost everything to solve the problem, without good results.

if someone please could try the script and try to figure out the problem, I would greatly appreciate it.

Here is the code:

curvesCA = attributes CustomCurves
   (
   	Parameters main rollout:CustomCV
   	(
   		cycle Type:#float UI:cycle Default:10
   		mult Type:#float UI:mult Default:30
   	)
   	Rollout customCV "Custom Curve"
   	(
   		CurveControl cc_test "Curve Control:" numcurves:1
   		spinner cycle "cycle:" Type:#float Range:[-1000,1000,10]
   		spinner mult "multiplier:" Type:#float Range:[-1000,1000,0]
   	)
   )
   max modify mode
   CustAttributes.add $ curvesCA
   $.cycle.controller = bezier_float()
   $.mult.controller = bezier_float()
   $.position.controller.z_position.controller = float_script()
   $.position.controller.z_position.controller.addtarget "cycle" $.cycle.controller
   $.position.controller.z_position.controller.addtarget "mult" $.mult.controller 
   $.position.controller.z_position.controller.addnode "obj" $
 $.position.controller.z_position.controller.script = "c = obj.customcv.cc_test.curves[1]
phase = (mod currenttime cycle)/ cycle
(getvalue c currenttime phase) * mult"
   

Usage:
-select an object
-run the script
-change the profile
-modify the cycle or multiply parameters if you like
-hit play

thanks in advance