Weird Glitch when installing Optifine

[deathbutton1]

Through many Google searches I have yet to find someone who shares this problem. I installed optifine 1.5.6_HD_U on tekkit lite, and after doing so, everything seemed to work, HD texture packs worked, I could edit the settings, but after a little ways in a noticed block breakers and turtles couldn't dig. This was interesting, because they would get the block drop, but the block would still exist. After this if I right click on the block or destroyed it the block would disappear without dropping anything. When it was in it's weird half-existing state it would have a hitbox, and behave like a normal block.

Then, I tried deployers, and I got the opposite happening: The block would not be visible, but if I tried to run into it I would bounce back (very similar to server lag).

Things I have tried:

1. Uninstall optifine (worked, but I want optifine )

2. Clean install and re-install optifine.

3.Create a different world

And yes, I put optifine in modpack.jar and deleted meta-inf.

Edit:

Reloading the world deletes a block that shouldn't be there.

Also, just realized redstone only gets updated when created.

I just want to say my guess is that a class that has something to do with how the server and client communicate got messed up when installing optifine

[diamondeye83]

Why'd you delete meta-inf from the modpack.jar?