I also have a parkside tracksaw, and just in the spirit of information, it let me down last week - badly - had to trim off some wood from the side of a door which is one of the most used tasks for a tracksaw, marked the cut width on the door top and bottom, lined up the track with those lines and made the cut.
offered up the door and..... it had a bigger gap in the middle than the ends, the track wasn't straight, somehow since the last time I used it, the sections have moved just enough to throw the track off perfectly straight along it's length.
I had to reglue the section back on (pinned it as well with airfed brads and managed to fire one into my thumb just for a good 'ole "f you" from the universe, on top of the issue I was now fixing) and once dry, recut it, making sure the track was straight, thankfully the door was going to be repainted again after trimming so got away with it - but my very first thought after I had sorted it out was "now those expensive tracksaws don't seem so expensive anymore" and now I've accepted I should pay the money, next time I need to use a tracksaw - which admittedly isnt that often.