Im trying to render a model, but parts of it are just inexplicably not there. Any suggestions?

Clip Start, Clip End

Could be camera clipping distance, or lamp(s) lighting distance issue. Check both of those in their respective properties panels. Also, do you have things on separate layers? If so you have to specify to render all layers, or move all to one layer.

I'm using Blender 2.62.0 after not using Blender for about a year and a half.

I'm having this problem as well, here are the details.

I've created an object which rendered fine. I then added an armature to the object and it no longer renders.

1. I've tried checking the camera, given everything else renders (see 2) you can guess that the camera's not the problem.
2. I've added other objects to the scene (they render fine)
3. I've checked the Renderlayer settings, they all show that all layers are to be rendered.
4. I checked that everything is checked in Outliner.
5. I've removed the armature, incase there's a setting that is causing this, there was no change.
6. I've created a new file and appended the object to the new file.

I've been searching the forums for a couple of days now and there is nothing to point to a solution. I really don't want to have to start over, again.

In a related matter, I've also come across an issue that the camera moves when I render an image. The only solution that works, temporarily, is to create a new file every time this starts to happen.
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SLJeans

I am having the same problem on 2.64. All of my objects are in the same scene, and I see everything in Rendered Viewport shading. When I hit F12, I see only a few items.

If I duplicate object that are displayed on F12, I see duplicated objects. If I duplicate *hidden* object, I don't see them.

If I make a new object, I see it in the F12.

I had the same problem.

I "once upon a time " activated under Object Data\Duplication the button
"Group" and forgot about it because I went another way then.

Once I checked "None" again it was rendered.