It may just be a setting that was not adjusted properly. The D300 has such a complex focusing system that it just takes a lot of time to get it set up right. Do you have a custom shooting menu set up for action/continuous AF shots?
Originally Posted by K1W1
Also, depending on the lens you used, that could have been the problem.
Nikon D300 | MB-D10 | Nikkor 12-24/4 | Nikkor 50/1.8 | Nikkor 70-200/2.8 VRI | Sigma 18-50/2.8 | SB-800 | SB-80DX (x4) | Radiopopper JrX Studio |