return $node->title; do not work in preview mode

hello, please help me with this issue, I know not that much about Drupal and can't solve it myself:

I generate text on image from node title and node body and it works fine if I submit my form but if I click on preview button on my CCK form I get image without text.
I guess this is because drupal do not creates nodes for preview mode that's why I can't see $node->title; and return $node->body; on my image. Is there any way to access these values from submitted form? I tried many things without any success, and even raised the same topic on forum here http://drupal.org/node/1158670 and described in short what I have done.
Please give a clue how to make this happen - click on preview and see text from my form's fields on the image.
Thank you!