plz help.... loading custom models.........plz help

every time a import a custom model it always comes up with a checked box. i mean every single one. downloaded some models from here, none of them worked, took some from other maps other people made and it worked on their map, but in another map, no. all the time i get the checked box. i dont no what im doing wroug. if u have a clean model, test it. but i dought it well work. what do u think i should do?

any one? am i lone in this scary world?

Read the tutorials, use the search function. That is a very common problem.