Help! User Authentication error message.

[ginatln]

Hello!
We are trying to integrate VM with Authorize.net. When using the test account, everything was working just fine.  Ever since I entered in our real log-in information, I get the following error messages after entering the test credit card number.

error: othercase: User Authentication failed due to invalid authentication values.

error: Failure in processing the payment (ps_authorize).

I would appreciate any and all input that helps towards solving these issues. Thanks in advance!!
Gina