Problem with ending [spoilers]

[flimsy steve]

Has anyone else had an issue with getting to the ending? I've cleared all the silver markers in Downtown and The Dells and according to a couple of walkthroughs I've looked at, there should be a silver marker in the junkyard where I can have a second conversation with Lynette (after the one where you tell her that Jimmy's dead) but the silver marker isn't there. Obviously a bit hard to pinpoint exactly what I might have missed out but I can't see any markers anywhere in any of these three areas and I can't access the school. Does anyone have any ideas at all how this could be happening or is it just broken? Thanks in advance.