Several have already mentioned the archery quest bug. Well here is something similar. I found a fruit for the alchemist cure quest, but I hadn't got the quest yet so I just picked it up as per normal. No problems. However, I went into my inventory and rearranged it, and when I moved the fruit the quest appeared in my journal. Even more, when I found the alchemist he talked as if he had already spoken to me. Since using the the inventory caused the archery quest bug it seems there is a definite link.