Question/Problem with Deep Sky Stacker using RAW

[Toxic Coolaid]

I've been using DSS for several months and have done very well with it. I use a Meade LX90 8in and a Canon T2i. I have been using jpegs for DSS and have just realized I can use the RAW images (Noob I know). When I use the Raw files DSS just shows a narrow thin rectangle for the images. It is a strip from the left side of my image, from top to bottom , but only about 1/8th of the image. This is what I get when I drop the files on to DSS, no registering or stacking done yet. I'm sure I just have a setting wrong, but I don't know what it is. I think it must be a setting with my Canon because I have older files from my 1000D and DSS shows the whole image. Can someone help me? Much appreciated!