A bug in Paul Neale Custom Attributes script,please help..

Hi...i am newbie in maxscript..I just learn how to add scripted custom attributes from Paul Neale's Rigging DVD Series,

but I found a bug from the script,
bug:
when I make several keyframes by dragging the spinner then i move any key in the trackbar,
the keyframe doesn't change its position in the trackbar simultanously (syncronize with mouse movement),
then when i release left mouse button,
and again keyframe doesn't appear in the frame target,
keyframe still on the first position when i created it..
Any body can help to fix this bug??please...
thanks..
sorry for my bad english :-)...