New couple of photos, and a question

Hello all! Firstly, I've been out and about with my Cosina and noticed a little problem. If anyonce can help it'd be most appreciated - have a look at the slideshow below:

Firstly, it's really over-exposed, I know. I was using Lomo 200 Slide film and probably should have set the camera to 400 to under expose it a bit. But there is a reoccurring theme of the light bar on the left hand side of each image - is this a sign of a light leak? I've not checked the seals around the edge of my camera back, I probably should...