Directory.EnumerateFiles => UnauthorizedAccessException

I Couldn’t get the above to work, but here is my implementation, i’ve tested it on c:\users on a “Win7” box, because if has all these “nasty” dirs:

SafeWalk.EnumerateFiles(@"C:\users", "*.jpg", SearchOption.AllDirectories).Take(10)

Class:

public static class SafeWalk
{
    public static IEnumerable<string> EnumerateFiles(string path, string searchPattern, SearchOption searchOpt)
    {   
        try
        {
            var dirFiles = Enumerable.Empty<string>();
            if(searchOpt == SearchOption.AllDirectories)
            {
                dirFiles = Directory.EnumerateDirectories(path)
                                    .SelectMany(x => EnumerateFiles(x, searchPattern, searchOpt));
            }
            return dirFiles.Concat(Directory.EnumerateFiles(path, searchPattern));
        }
        catch(UnauthorizedAccessException ex)
        {
            return Enumerable.Empty<string>();
        }
    }
}