Two Customer Account Problems

[lwheelr]

Upgraded store to 1.3 RC3. Yeah, I know, NOT for live sites, but I inherited this client after the previous "pro" had been running SVNs on the site, so needed to upgrade.

Having issues with account creation and login.

Customer account creation gives this error:

There is 1 error :

01. an error occurred while creating your account

No clue WHAT the error is. All required fields filled out.

Customers trying to login get error messages, Invalid Password messages, or Invalid Token messages. This problem varies, is intermittent, sometimes works, sometimes does not, and we have not been able to spot a pattern to the errors.

Any suggestions as to where to start appreciated.

Laura