Dear carlobot,
First and foremost, if you need other forumers to aid you in your doubts, please address the question in a clear and understandable manner. I do not mean to lecture, but as an undergrad - which i presume you are - you are suppose to be able to derive question which will lead to your answer. How are we suppose to help you when we do not understand the whole situation?
As a start, can you please elaborate your problems again? Starting with the few tests you have done on the projects. I've read something like you have done few testings, you have connected your pins to your motor, then something happened. Then, you connect them to another pin, and something different happened. Can you please write the tests you've done in paragraphs or itemize them? It will be easier for us to answer your question if you do it in a systematic way.
Lastly, I'm sorry for my bluntness but it is only because I'm curious to know the problem and anxious to see your project working. Do try to draft your questions before posting them! Looking forward for your reply soon...