Add Variable does not work correctly

Im on d6.10 on apache 2 and php5 on ubuntu (But this happens in other platforms as well)

create a rule,
add an action,
add new number variable,
type in the number 123,
change label to "My Number",
change machine name to my_number
save it
add an "Execute custom PHP code" action with a weight of 10 so it executes after the one above
note at this point the system tells you that $my_number is a valide and available variable.
in the code write this: drupal_set_message("my_number was".$my_number,'warning');
save it and trigger it.

#

    * 0 ms Content is going to be saved has been invoked.
    * 13.753 ms Included MODULE.rules.inc files.
    * 14.509 ms Executing the rule Switch trigger on rule set Content is going to be saved
    * 14.803 ms Condition Saved content's field 'field_switch' has value evaluated to TRUE.
    * 15 ms Condition Saved content is wxrecord evaluated to TRUE.
  
  * 15.172 ms Warning: Unable to get variable number.

    * 15.24 ms Element Add a new number variable has not been executed. There are not all execution arguments available.
    * 15.362 ms Action execution: Execute custom PHP code
 
   * 15.46 ms Warning: Unable to get variable my_number.

    * 15.481 ms PHP is not evaluated as there are not all necessary variables available.
    * 15.569 ms Evaluation of Content is going to be saved has been finished.

I think what happens is that even though we are given the ability to edit the machine name of the variable, it looks likes it is hardcoded to look for *number* instead of the real unique name I entered , this happens with all variables like this. so we are limited to one of each variable since we cant change the unique name.