not being sore the day after working out is fine...in fact for me that is normal, ...it seems that the lactic acid doesnt cause any pain untill two days after i workout...and then it sowly drains as the muscle repairs....
if i wasnt getting sore at all, i would try working out all my muscles every day, because if they arent sore, than they are already repaired....and i could put on muscle like nobodies business.
but thats me &&& how my body works.....dont know about you guys.
i suggest you just turn up the intensity up a bit.