The problem is not on the unwrap. It is the size of some textures by Ric! 3072 or 1536 pixels are not dds compliant ;). Bring the textures in the right size and all is well.
PS. The Su-25t Cab also use Textures from the zip's Cockpit-SU39-TexturesBMP, Cockpit-SU39-TexturesTGA, CockpitsPlatinumBMP, CockpitsTexturesBMP, CockpitsTexturesTGA ;).
Fast Test with the PRIBOR-39-MAINPANEL.bmp.dds: