I guess Phemox means that you should convert the terrain detail textures into another format like .bmp and use them instead of the .tga files.

Just look for these files in your folder:
Code:

bmap detail_texture1=<icx_detail1.tga>;
bmap detail_texture2=<icx_detail2.tga>;
bmap detail_texture3=<icx_detail3.tga>;
bmap detail_texture4=<icx_detail4.tga>;

an convert them to .bmp (e.g.)
Then change the code to the new files:
Code:

bmap detail_texture1=<icx_detail1.bmp>;
bmap detail_texture2=<icx_detail2.bmp>;
bmap detail_texture3=<icx_detail3.bmp>;
bmap detail_texture4=<icx_detail4.bmp>;