FYI I have received the following Customer Support Alert so it looks like I'm not the only one!
Somehow that makes me feel better
🙂Latest Alert:Intermittent System ErrorsA handful of customers may encounter system error messages while using Marketo. Our team is actively looking into the issue and we will provide updates as soon as they are available.
Publish Date:- Thu Jan 15 00:00:00 GMT 2015