THIS_SCRIPT issue

[soniceffect]

Hi Guys,
Seem to have a problem I cant solve.

In the top of the main page of my new modification I have the following

PHP Code:

define('THIS_SCRIPT', 'dcSomepage'); 


The first line in one of my plugins is

PHP Code:

if(THIS_SCRIPT=='dcSomepage'){ 


Now this works absolutly fine on my dev forum as I have been coding. However once I tested the installation of my modification on another installation I found that my main page was blank. On further looking it seems like THIS_SCRIPT wasnt set on first run. If I comment out the if block and run it I get my page fine. I can then safely put it back in and it works without an issue.

Please could someone let me know what Im doing wrong? Got a good modification I wanna release and this annoyin bug is the only thing stopping me LOL

EDIT: Odd thing is it worked on default skin, just not my custom skin ... Very strange