Getting an ArrayList back from ObjectInputStream (JDK1.5)

Here is my code:

/**
* fetchGremlins method to read a file and provide list
* @param fileName String
* @returns ArrayList<Gremlin>
*/
public static ArrayList<Gremlin> fetchGremlins(String fileName)
throws IOException
{
ObjectInputStream ois = new ObjectInputStream(
new FileInputStream(fileName));
ArrayList<Gremlin> list = null;
try
{
list = (ArrayList<Gremlin>) ois.readObject();
}
catch (ClassNotFoundException ex)
{
}
ois.close();
return list;
}
// end fragment

It works, but on compiling I get the compiler warning about unchecked
or unsafe operations. I am assuming this is to do with generics in
Collection classes (ArrayList), and that the problem is the cast. Can
some kind person help me with the syntax to get rid of the warning and
have safe operations?

.