d50 Focusing Issues...

[PHeller]

In messing with my new 50-150 Sigma, I seem to be running into auto-focusing issues with my D50.

For some reason, it refuses to auto-focus anywhere near the minimum focusing distance of the lens, and at distance it seems to hunt around for the subject that is in the middle of the frame.

This is frustrating because I can't count on the AF to hit the subject when I take quick pictures of a "once and done" opportunity.

Is this the lens, camera settings, or user?

[Stoller]

In messing with my new 50-150 Sigma, I seem to be running into auto-focusing issues with my D50.

For some reason, it refuses to auto-focus anywhere near the minimum focusing distance of the lens, and at distance it seems to hunt around for the subject that is in the middle of the frame.

This is frustrating because I can't count on the AF to hit the subject when I take quick pictures of a "once and done" opportunity.

Is this the lens, camera settings, or user?

Can I suggest digitutor, make sure you watch the section on Focusing and Choosing the AF-Area Mode. If your new to the D50 its a good place to start with the basics.
http://www.nikondigitutor.com/eng/d50/