Hi Nicolai,
I don't have an answer for this, but currently there is no easy way to manage RAW files on the N900 using Camera-UI2. Right now what I do is move Camera-UI2 DNG's to the same directory that FCAM is using. With FCAM I can then review the RAW file sand delete them. The RAWs are very similar and all it does is pull the thumbnail anyways so its not that difficult.

RAW Viewer lets me view photos but does not allow me to do any deleting. I can use the regular file manager and just look at the associated JPGs but the thumbnails are small.

Anyways, I have no easy solution but wanted folks to know that FCAM does a good job of managing the Camera-UI2 DNGs on the N900 for those that want to use it.