Thank you so much again windhunter!  With some outside help I've managed to fix my issue.

It's because of filesize; regular Snake's .pcs files are all less than 600 KB, and I would recommend going no more than 577; possibly less. You can lower filesize by exporting the textures, lowering the texture resolution in MS Paint, and replacing the textures with those lower-res textures; preview the model, though, just to make sure that it doesn't look crappy. No money needed.

Thank you so much! You're awesome!

I managed to get it to work in-game without freezing by exporting and reducing the texture size; tried reducing them all by 50% and 75%, but then a new problem occured... the mapping for the textures gets all buggy (He's got green on his face and purple on him and stuff, it's all everywhere because they aren't the original size.) I also tried exporting the original png files and turning them to low-quality jpg's to no avail (still froze as the pac was over 1,000kb).

It's weird because in costume manager the textures pop up on the model fine when they're resized. In-game they're just crazy though.

Do you have any tips on how to make the file size smaller without affecting the actual dimensions of the image?
Or - preferably - resize the image but keep the textures mapped properly?
When I resized them I just used picresize.com, which usually works in most situations and comes out very high quality.

Thanks again!

In advance: I'm sorry if making paypal deals isn't allowed here (although I saw a few other threads doing this)

I really, really, would like to play as jokekids joker over snake in P:M (3.0), here's the link: http://www.mediafire.com/download/8b89o2kmg9f3k2q/FitSnake04%28joker%29.pcs

In P:M it just freezes on stage selection. Literally everything else I've managed to get working; but no matter what I try, I can't get this to work! If anyone would like to help me out, bless your soul and THANK YOU. I got 10$ to throw at ya!

Thanks guys <3