Sorry, I dont belive this at all either. UNless half keys are considered non rare drops. I got 2 half keys in a row from the same desert lizard (the higher level one) and Im positice there wasnt a sever update in between.

I don't know if it's relevant to the topic or not, but I've killed my share of Lessers looking for Rune Meds myself, and I did notice a vague pattern to the drops. It went something like: Gp (x10-20), Fire Runes, Gp (15-30), More Fire Runes, more gp, Gold Ore, more gp and sometimes Runes, mid-lvl armor or weapon (black shield or mith something), even more gp and runes, then the Rune Med (or at least something very similar...it was a while ago). It wasn't exactly the same every time - sometimes the mid-lvl armor would be skipped or the Ore would come sooner than expected - but it generally went that way every time I went down into Karamja Volcano. It got to the point that I knew just about exactly how much food to bring to get me to the Rune Med drop.

 

Like I said, I don't know if it's relevant, but it's something I noticed and thought I'd point out.