Lag 1.7.2 with non solid blocks

Hello,

I've been experiencing problems regarding non-solid blocks (flowers,grass,ladders,tripwire hook, rails, and torches being the main problem).
Whenever I or another player holds any of those items in their hand, my FPS drops to 0-15. This only seems to be the problem in 1.7.2.

I've recreated the .minecraft file.
I've configured the settings I can.
I've configured my graphic card settings to the most optimal performance for Minecraft (30-50 FPS)

This never happened before but now, what's the problem?