Ok, so the comma separated string of numbers means that validation is failing on the form which is preventing it from submitting.
the numbers 4 and 5 refer to the Captcha and Security Question validation.
My guess is that the server is not configured to store session variables.
Try the session test page from the following post to test the servers session management:
if the test fails, then you will need to contact the host to have them correct the problem.
most likely it is a bad setting for the session.save_path in the php.ini file.