Both in Single player and on the server I am hosting to test a custom mod pack I'm working on (waiting for both carpenters blocks and build craft to be updated completely so i thought I'd help by giving feedback) I get a weird display issue from all of the blocks in update 3.4.002. Attached are pictures showing the issue.

Ok, defiantly works without optifine... could part of the problem be the fact that optifine prepares objects using multiple cores instead of the normal 1 core with regular minecraft rendering?

Something along those lines. I played it safe with blockstates, but I guess when it renders a model some other resources are shared that I was unaware of (at least when Optifine is present).

I've messaged Optifine author. I tried a quick fix but nothing improved; need to understand better what Optifine is doing behind the scenes.

This is a known issue with Optifine. I will look into this as soon as I have time.

I've tested this with the Optifine version C7 released today and this issue still exists.

I opened an issue and got some feedback from Optifine author here: sp614x/optifine#1054

It may be VertexFormat causing an issue, but I have not have a chance to look into this yet. Once I finish working on slope things I will try to figure this out.

For what its worth my testing was done with shaders off.

It might've fixed the issue with another mod, but I think this one has to be resolved on Optifine's end, if necessary. UV is not the only thing affected - we're seeing color shifts, unexpected vertex translations, etc. I don't know the extent of a fix for this, but disabling the custom VertexFormat will have minimal impact on this mod (only the Carpenter's Safe utilizes the feature).

@Mineshopper this fix to forge: MinecraftForge/MinecraftForge@c12df92

Did not resolve the texture rendering issue encountered with Optifine with CarpentersBlocks.