Invalid data element is usually a communication setting issue, where the server between your BlackBerry and our servers is not communicating as expected.
Does the same error happen when you try all three TCP Choices? Have your tried rebooting the BlackBerry by removing the battery for a few seconds - this often helps with basic communication issues.
We suggest contacting our support center by using this web form:
REXwireless Software Support Center
Thanks,
--the REXguys--