If you install Project Red and iChun's Portal Gun mod, the PR lamps display the wrong textures on the first game run. If you restart the game (not just reload the world), the issue corrects itself.

This was tested with the newest version of each mod and only included these two mods + dependencies.

CodeChickenCore 0.9.0.5.jar
ForgeMultipart-universal-1.6.2-1.0.0.167.jar
iChunUtil2.2.0.zip
PortalGun2.0.1.zip
ProjectRedBase-1.6.2-4.0.0.2.jar
ProjectRedIntegration-1.6.2-4.0.0.2.jar
ProjectRedWorld-1.6.2-4.0.0.2.jar

This appears to be due to the file PortalGunSounds.pak which gets unpacked into the mods directory. If you delete the file it will come back on next run, but the texture glitch also returns. I'll notify iChun as well.

Also of note is that Project Red's lamps have conflicting IDs with Factorization 1.6.2 beta 13; this appears to be an unrelated problem though. Mentioning here because it mislead me for a couple hours.

Can we get some screenshots?

Here is what the tab looks like on first run.

http://i.imgur.com/0fnR4Py.png

If it's a one time thing then I don't think we should be too worried about it then tbh

Agreed, i can't reproduce this. Must be something else.

Does ProjectRed only load textures once when resource packs are reloaded?

As far as these lamps and such are concerned, they don't do anything special. They load textures in registerTextures() and thats it. Lamps rebind the terrain atlas as well.