How to compare sql database column value with IsolatedStorageFile content in C#?

Question

I am developing a program that needs to compare a key from a database column with IsolatedStorageFile content. I'm able to get both the column value from the SQL database and also the file content from the IsolatedStorageFile. However, I am not able to compare both files to see if they match.

Here's my code that gets the value from database column:

using (SqlConnection sqlConn = new SqlConnection(ConnString))
{
    int dbID = 1;

    SqlCommand sqlCmd = new SqlCommand("SELECT serialKey FROM activationTable WHERE id = @id", sqlConn);
    sqlCmd.Parameters.AddWithValue("@id", dbID);
    sqlConn.Open();
    string dBSerialKey = sqlCmd.ExecuteScalar().ToString();
    Lbl_CheckDB.Text = dBSerialKey;
}

And here's my code that gets the content from the IsolatedStorageFile:

using (IsolatedStorageFile isolatedStorageFile = IsolatedStorageFile.GetStore(IsolatedStorageScope.User | IsolatedStorageScope.Assembly, null, null))
{
    if (isolatedStorageFile.FileExists("Settings.txt"))
    {
        using (IsolatedStorageFileStream isolatedStorageFileStream = new IsolatedStorageFileStream("Settings.txt", FileMode.Open, isolatedStorageFile))
        {
           using (StreamReader streamReader = new StreamReader(isolatedStorageFileStream))
           {
              string readLine = streamReader.ReadToEnd(); 
              Lbl_CheckUserKey.Text = readLine;
           }
        }
     }
 }

And here's how I'm trying to compare both keys:

if (Lbl_CheckUserKey.Text == Lbl_CheckDB.Text)
{
   Lbl_BothKeys.Text = "Valid Keys!";
}
else
{
   Lbl_BothKeys.Text = "Invalid Keys!";
}

I want to be able to compare both keys, and if they are the same, it should update my Lbl_BothKeys.Text = "Valid Keys!";
But the result that I keep getting is: "Invalid Keys!", even when both keys are the same.