See the example below for a masking problem.
In the picture, the first image is a straight assignment of the image to a sprite.
The second image is built from 2x subimages. Notice the masking problem when using the subimage method.

An example project is attached.

Can someone verify I haven't done something wrong before I submit this as an urgent bug?

thanks

Image of problem

I have had this problem, even with single images loaded up also. Just use this at the start of your code.

Ah, nice one.

Thanks!

You may also want to look at the SetSpriteUVBorder command since for sprite sheets it defaults to a half pixel border that prevents the images blending into each other. However if you are using sprites that match perfectly to your resolution you may be better off with a border of 0.