The rear wheel is straight and as far as I can determine the rear triangle is straight too. However, the front forks do look slightly askew and there are more than one loose spokes on the front wheel.
Here's another symptom related to the tracking problem. I performed this little experiment this afternoon. I stood the bike up and while standing beside it I held onto the seat. I had the front wheel pointing straight ahead and the bike was in a perfectly upright and balanced position. When I let go of the handlebars the front wheel immediately turned all the way to the left.
I just got on here a few minutes ago so I haven't had a chance to check out the links FRANKIEJ.