When using a transparent texture on a quad in the world, I get an artifact as seen here:
   
That vertical line only shows up when I have a texture that is not a power of 2. I'm working on something of a 3D menu, so performance is less critical than exact alignment(which is easier to do without the padding from increasing the texture to the next power of 2). [I'm still futzing around with it to find out if it's worth while, or if I should just work on figuring out a way to align everything with the power of 2 texture.]
Is this artifact caused by the engine, or by the hardware/drivers?

Hi,

This is related to the nearest pixels around that area:
-texture filtering
-texture address mode (wrap/clamp)

try setting 1 extra transparent pixel line around that area, or if that's the end of the texture, then perhaps, clamp tex addr mode?

Thanks, I wasn't able to find anything about the tex addr clamping; however, turning off the filtering did fix it- but then the texture looked really bad. :( I'll see about making a way to work with it as a power of 2.