My thoughts could be that the tiles you are standing on are conflicting. I have never seen this before.... Could you provide and image or a video of them both working and non-working?
Definitely, here's a YouTube video: http://youtu.be/HblZ9n9HK8Y
The first part is the working script, the second one is the failing script.
I do also have a picture:
The highlighted event is the one working script, and there is another script event directly under it for something completely different. The two script events on the side also have the same script events under them, and they also have a warp under that which serves no purpose. And I have tried moving the script events under the broken ones somewhere else, but no dice. Same thing with the warps.