Hi All: I never use my 300 without the TC 1.4 or 1.7. Today for the first time I put in on both my D70 and D200 without a TC. There is definitely a "squeal" coming from the lens when it focuses from either infinity to shortest distance or from shortest distance to longest distance. It is of course move significantly faster to focus without the TCs. I would assume that this means trouble with my AFS. Anyone here had that symptom?