Hi gibblyweeds, you can have more than one project open, but you won't get both onto the same timeline. To get around this, load one of them and under File, go to export movie and choose one of the formats you see. Save the video file and remember where you are saving it to. 

Now close that project, and load the other one. You can now add the actual video file of the other project to this project on the same timeline. Cheers, M o' L