Blank Screen Every Render

I've been studying the SDK and the tutorials for quite a while now, but it's getting difficult to progress since the basics don't seem to work.

My ultimate goal for now is to just successfully render objects to show up in the Simulator.

Following tutorials 2 and 3's videos, I recreated the scenes and the .sio2 files, and renamed the original ones as to not lose them. I re-linked the new .sio2 files, and build and go.
Nine times out of ten the screen will render completely black. Every once and a while I can get the object to render, but always texture-less. I read a while back to make sure to export strictly triangles, which I am doing.

I'm running Xcode 3.1.3, Blender 2.49a (didn't work when I was running 2.48 either), and SIO2 v. 1.4.

Any help would be GREATLY appreciated.

Does your texture is a power of 2?

Did you make sure you had all objects (including light & camera) selected before exporting? Also, if you changed the name of your scene and/or object, you'll need to change their names in template.mm and it might be helpful to delete the previously exported sio2 file and folder and export fresh as opposed to doing an update. Finally, make sure your textures are a power of two (256x256, 512x512, 1024x1024).

Thanks a lot for your time, first of all.

To answer both replies,

I am actually using the exact texture from the tutorial that is inside of the SDK, so I am pretty sure it's a power of 2.

And I am certain all objects are selected, and can double check that they exported in the .sio2 file
when changed to a .zip.

Sorry to turn down these suggestions, but I'm still not sure what's causing this to happen.

Does it render properly in Blender?

I'm not quite sure what you mean by that... I'm creating the scene in Blender to render in the simulator following tutorial 2 and 3, and that's where it doesn't seem to be showing up.

And sorry about missing the second part of your post cdicelico, but what I'm doing is deleting the .sio2 from the Xcode project, and renaming the original to something like "tutorial02_original" for example, so I don't lose it, and exporting the new scene as "tutorial02" in the data folder, and then re-linking that to the project window.

Alright so I've gotten objects to finally show up in the simulator, but textures just don't seem to work. I noticed that the video tutorial was using an older version of Blender, so the process of applying a texture is a little different, and I was wondering if anyone could update that procedure, since my method seems to not be working.

Thanks again.

Absolutely nothing have change in that procedure...

Wow you're absolutely right, for some reason the texture Blender bricks were not showing up where I expected them, but I have found them now.

Well thanks everybody for making me go back and check my work, I think I have it covered for now.