Delphi program using DCPcrypt does not decrypt from PHP after upgrade to XE2

I have an application developed in Delphi 2007 in which a value is encrypted by PHP and decrypted in the application. Encryption algorithm is RIJNDAEL 128. When I moved the XE2 and installed the latest version of DCPcrypt the application run but is no longer able to decrypt the encrypted string from PHP. The result appears like Chinese characters so I am wondering if I need to modify my handling of the encryption key, vector, or encrypted string to account for the fact that XE2 uses Unicode characters.

The PHP encryption is performed by the following: (mcrypt_cbc(MCRYPT_RIJNDAEL_128,$key,$date_str,MCRYPT_ENCRYPT,$iv))

And the two relevant Delphi functions are here:

function PadWithZeros(const str : string; size : integer) : string;
var
  origsize, i : integer;
begin
  Result := str;
  origsize := Length(Result);
  if ((origsize mod size) <> 0) or (origsize = 0) then
  begin
    SetLength(Result,((origsize div size)+1)*size);
    for i := origsize+1 to Length(Result) do
      Result[i] := #0;
  end;
end;

procedure TfrmMain.btnDecryptClick(Sender: TObject);
var
  Cipher : TDCP_rijndael;
  Data, Key, IV : string;
begin
  // Pad Key and IV with zeros as appropriate
  Key := PadWithZeros(boxKey.Text,KeySize);
  IV := PadWithZeros(boxIV.Text,BlockSize);
  // Decode the Base64 encoded string
  Data := Base64DecodeStr(boxCipherTextIn.Text);
  // Create the cipher and initialise according to the key length
  Cipher := TDCP_rijndael.Create(Self);
  if Length(boxKey.Text) <= 16 then
    Cipher.Init(Key[1],128,@IV[1])
  else if Length(boxKey.Text) <= 24 then
    Cipher.Init(Key[1],192,@IV[1])
  else
    Cipher.Init(Key[1],256,@IV[1]);
  // Decrypt the data
  Cipher.DecryptCBC(Data[1],Data[1],Length(Data));
  // Free the cipher and clear sensitive information
  Cipher.Free;
  FillChar(Key[1],Length(Key),0);
  // Display the result
  boxPlainTextOut.Text := Data;
end;