3d MODELING TIPS:
> The best way to make your 3d model find its textures is to make it saved/exported not just in both directory but in the root directory of your hard disk (C:\). With this you can use your 3d models properly for any use even on web based applications.
> Use as small image size as possible. You may use DIETJPG /VSO-Image-Resizer to optimized the Jpg images (compress file size without loosing quality)