I'm just trying out the mod and I really like it but I have a problem that whenever I try to smelt iron at the beginning of the game I am unable to as the furnace does not seem to recognize it. Any clue why this may be happening?

I just thought I should clarify the furnace is also fine as it can smelt cobble to stone just fine

What version of the mod are you using, and with what mods?

Should be fixed in latest.