My impression was that BOINC was insisting on a login with password for user on the machine -- I don't use a password so it got confused
I think that part is just if you want to run it in server mode. It seems to run fine for me but you have to stay logged in to the machine, which I do anyway.
If you aren't using BOINC you really should. I received a new machine at work at the beginning of the Summer and it is dual core. I was running the UD client and was returning about 3 results a day. I installed BOINC yesterday and it started using both cores at the same time and has returned 9 results in 24 hours. Even counting only one core that is still 4.5 results per processor instead of 3 for both together. I'm also getting more points per result since installing BOINC.
The only "drawback" is that you only have a week to return the result. The reason for that is that every result has to be calculated by three different machines. You don't get credit for your results until two other people have returned the same result. If at the end of the week three results aren't returned the job is sent out again to a different machine. Eventually you will get credit but it can take a while. This is a problem for my installation on my laptop because I don't get enough time on it every week to even return a result and I hold up other people.