Parenting with automatic weight, not working?

Hello to all, first let me introduce myself, my name is Adrian and although I’ve been playing with Blender for a while now I’m still learning a lot about it, and with the upcoming release of 2.5 I’ve been playing even more with both versions, 2.49 and 2.5. So now to my question, I’ve been following the tutorial of “introduction to character animation” in the blender website and up to the rigging part I was ok, but then I couldn’t figure out how to do the leg rigging since I couldn’t understand it. So I decided to move the already modeled character to 2.5 where I followed BlenderCookie’s tutorial on rigging (“Rigging an Alien”) and I was able to complete the armature but the problem is when I attach it to the mesh like the tut says (by parenting with the automatic weight) it deforms the mesh really wrong. So what am I missing? I tried this several times but it keeps doing it, no matter what way I try. Here I live the example of what happens. It is as if some sort of proportional editing was going on (It isn’t). I appreciate your help a lot and I apologize for using this thread to introduce myself too, I just thought I might as well post just once.
Thanks!

http://img28.imageshack.us/img28/9695/screenshot20100307at104.png

It would be helpful to see the wireframe of the character but it seems like you don’t have enough vertices aroud the joints in the deformed mesh. Also before applying the automatic weights make sure the bones are positioned right (check from several views).
If you think it is a bug you should check if you get different results in 2.49 first.