You more than likely forgot to change the Alpha to black, just my guess.
Thank you very much! Can you give me more details?
What type I choice?
DXT1 RGB 4 bpp | no alpha
DXT1 ARGB 4 bpp | 1 bit alpha
DXT3 ARGB 8 bpp | explicit alpha
DXT5 ARGB 8 bpp | interpolated alpha
DXT5_NM XY 8 bpp | using DXT5
3Dc XY 8 bpp | Normal Map
palette RGB 4 bpp | 16 colors
palette RGB 8 bpp | 256 colors
palette ARGB 4 bpp | 16 colors + alpha
palette ARGB 8 bpp | 256 colors + alpha
8 A 8 bpp | alpha
8 L 8 bpp | luminance
8.8 AL 16 bpp | alpha/luminance
8.8 VU 16 bpp | signed
8.8 CxVU 16 bpp | signed
8.8.8.8 QWVU 32 bpp | signed
16.16 VU 32 bpp | signed
16f R 16 bpp | floating point
or other?
