TOPIC: No registrations being created

I see this is a common problem, but in our case we are running the latest and greatest everything, including DTR 3.1.1, and we are simply testing the product with dummy events and dummy registrations, and none of them are working. There is no Paypal involvement at all. I look at the DB directly and I see no evidence of a registration being created (and of course, no mail goes out).

When I try to register, I get the usual thank-you screen, but also the following message:

"Strict Standards: Only variables should be assigned by reference in /home/oauamacu/public_html/components/com_dtregister/views/message/tmpl/default.php on line 12"

I'm sure that's a clue to what the problem is, but I don't know enough to decipher it. Any suggestions?