Fire Sprite Effects Glitch

[Jetroid]

Hey, I have a problem with the fire sprites in my copy of the game. This problem occurs in both vanilla and modded versions of the game. At the 'edge' of the plane which clearly holds the sprite for fire and such, there is a line of pixels. Whilst this is a fairly minor issue, it *IS* bugging me: For instance:
http://cloud-2.steampowered.com/ugc/615021010586096169/A626B7676952D65EF7EF28232CF4725A8259E306/
http://cloud-2.steampowered.com/ugc/615021010586075039/3E93C5B7F5B7CB642DF7AE7CE8F0B92FDD8D8861/

The problem can be seen in these two screenshots. Those with smaller resolution monitors may have to zoom in.

Does anyone know what causes this? Can you help me?