Descartes in the way

The biggest complaint I have about Descartes as compared to IRAS-B, is that the rasters now get in the way. It was nice when the rasters used to be on their own layer and any work I did with the vector drawing did not interfere with the rasters and vice versa. Now, everytime I do something with the vector, I have to make sure I de-select the raster or the same tool effect will apply to the raster. Is there any way to "lock out" the raster so I can do what I need with the vector without accidently deleting or moving or copying (or whatever) the raster? This idea of putting the raster on the the same layer as the vector has really slowed down my production.