Thanks, ModelsPlease. Though I didn't use the fixed file you sent me(sorry!)-- before I saw your mail, I changed some parts of that texture and I don't want to do it again -- so I just modified mine according to the way you fixed it. (Very smart... use the hull color to replace the black background. )
Here comes my final retextured Fek'lhr class -- with hull textures, damage textures, growing groups, and GUI shots(BS/TI/VL.bmp) changed -- you can get it in the attachment of this post.
As I said, don't expect too much... I'm still new at this field... only know some graphics editing skills.
[edit]re-attach the file with readme included. Thanks again, ModelsPlease.