Using ZModeler, some options ( like reflections ) could be set automatically in the default installation...But this is not a problem, since, as previously said, You can uncheck this option in Material editor.
regarding tga files in the work folder You are using with ZModeler, You can't directly update those...If You have a tga file ( for example tga 1 ) and You want update it with a photoshop program, You can work tga file, but then You must reconvert ( with GP4 Master ) in tex file, and then again ( always with GP4 Master ) You must convert tex file in tga file, in the ZModeler work folder.
Only in this way updated tga files will be shown in a correct way in ZModeler ( otherway, You may see it flipped ).
nicol@cciarri