Hmm I understand in the case of stone, glass, etc. But the woods species is different because, each wood give you a different blocks and you can't obtain acacia in the crafting table with dark oak I mean you dont need a wood for obtain another one, it's not logical. I think is design flaw.
Still in the 15w40b but only if the sound is completely over (if you stay more than 3 seconds writing) but if you place a sign and click "done/scape" immediately it does not happen.
Confirmed for 15w40b