As a first thing, if the output image in DSS is coming out as a strip down the screen then you probably need to use the beta version which can be found here....
http://groups.yahoo.com/neo/groups/DeepSkyStacker/info
Also when DSS autosaves a TIFF in generally does it as 32bit which Photoshop doesn't like so if you can save the result as a 16bit TIFF it may help.
You have a number of things to work through there and you will get there in the end but I think the first step is to download the beta version and see if that helps things.