Some Super Secret Settings don't show the writing on signs!

I think the square could also be a bug but I'm not experiencing it on every resource pack.. why?

Still a concern in 1.7.4/5 and 14w08a with "art" shader.

Confirmed for 14w18b.

Is this still a concern in the current Minecraft version 14w30c or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

art.json looks like it doesn't show it, but the shader itself makes it just nearly impossible to see. Same for blobs2.json.
Closing as WAI.
For reference: art.json very close to the sign: http://i.imgur.com/NQzcO30.png