Hey guys, So, I'll try to keep this short (difficult for me, so remember I'm trying). About 3 times in the last 2 months I've had a weird situation with my 300 f/2.8 AF-S II and Nikon TC17. The camera (or lens as it may be) refuses to even try to auto focus. When I take the TC 17 off and mount the 300 f/2.8, it AF's just fine. Now, that would seem like an obvious TC problem...EXCEPT...when this is happening, if I mount the TC to my 70-200 it AF's just fine. Then, after a while it has always started to AF with the TC and 300 f/2.8. Yesterday, I tried for over an hour...the 300 f/2.8 would work just fine solo, but would not work at all with the TC...when I got home (extremely frustrated from missing a day of shooting the way I wanted to, I mounted the 70-200 with the TC 17 and it worked fine). After mounting the TC and 70-200, I gave one last try with the 300 and TC and voila it worked. I am confused as if this is a TC problem, why does it work with the 70-200? If this is a lens problem (the 300 f/2.8) why does the lens work perfectly on it's own? Any ideas? My biggest problem is that I purchased the TC 2 years ago before understanding the consequences of buying a gray market product from Nikon...so the TC is the ONLY thing in my bag that is not a US model. I guess my other fear is that the 300 f/2.8 is one I bought used and while it has been an exceptional lens for me, I'm not sure exactly how old it is and wouldn't have a clue as to what it might cost for me to get it repaired should it need it...but then again, it works fine on it's own. Ok, I'll stop writing now, any ideas, suggestions, etc. would REALLy be appreciated.