This is a good thread to catch! I've had these problems with the cracks on the tongue, no mouth ulcers but the tounge issue persisted for quite a while and I was very concerned. I have not had this issue since I stopped using my aspire K1 clearo's and moved on to stainless steel RDA's and a kangertech subtank nano. I'm guessing the chrome allergy is most likely the case. My tongue got so cracked up I though I may have had cancer!!! No irritation at all since I switched to stainless. Can anyone confirm that Aspire K1 drip tips are chrome plated?