Update to 2.1.8, supposed to be the last update for a while from the Infitech2 devs.
Mostly just pushing these updates through atm as the nether keeps giving awful memory leaks making trips to the nether nigh impossible.
DOWNGRADE to 2.1.6, anything above gives serious problems when going to the nether. I've notified the mod author, awaiting fix. 2.1.6 however is a lot more stable for now.