BOINC by itself doesn't crunch a thing, it's a managing program. You need to attach to a project to do something with it. Not all projects have a graphics option build in. Only a handful of them do.
I'm calling this not a bug. If you have further questions, go to the BOINC forums, register there and post questions. That's where we can help you further. When you do post there, make sure to add more detail, such as which OS, what kind of videocard, DirectX version, which projects you're attach to etc.
(Do not post your email address in a legible form either. The spam bots reading those forums and this here Trac love that).
