I'd like to chime in that the atomizers being out of spec may be the likely problem. I had the same thing happen with a few 901 atomizers. Ended up using a metal washer to make them snug.
xisox has a 510. Sounds like the suspect 801's are about .003 out of specThats about all it takes to squish the insulators that is used in most attyies. LOL sounds like a 5 o'clock atty eh?