Hmm. I think we'll need more information to know what's wrong. Try this: get aMule frozen. While it is frozen, open Applications -> Utilities -> Activity Monitor. You should get a window showing all of the processes running on your computer. If not, choose "Activity Monitor" from the Window menu.
Find the entry for aMule. It should be in red because it is not responding. Double-click on it. In the window that comes up, press the Sample button. It will work for a few seconds and then show a table of information. Use the "Save..." button on that window to save that information to a file and then attach that file to a reply to this thread.
Now you can Force Quit aMule and quit Activity Monitor.