Conflict with WordPress Zero Spam plugin, accounts don't work.

With the incredibly great WordPress Zero Spam plugin enabled, the "New Account" form that you get from the /classifieds/signin page throws an error that there was a problem processing your registration. It bounces you to the default WordPress account creation screen (with the logon and email address you entered previously populated already). Only from there, when you click the submit button again, does the account get created and the email with login information go out.

But a bigger problem. Once I log in with these new credentials I get the Classifieds Checkout headline with "This feature is currently disabled by the system administrator."

Huh? The new account has the new role I created of "Advertiser," and Advertiser has been assigned all the capabilities except "Edit others' classifieds" and "Delete others' classifieds." What more needs to be enabled?