Where did you get your glass? I am betting bartamos' last nickel that your glass is too thick. Four vendors can't be wrong when no one else is having the same issue.
1. Quote from Roy: "
The glass is 1/4 (.250) thick and when the "felt strip" is installed it closes down some."
2. You are correct that four vendors can't be wrong.........so hence my "two bit" explanation about division bar being damaged or old run channel not removed.
3. Gord is right about glass being tight after a window restore. It will loosen up after awhile but this is hard to imagine: From Roy: "If I have the vent assy on the bench (Not in the door) with the felt runner mounted in the division bar. I can not pass a piece of glass thru the felt track."
4. For now I will have to lean towards Gord's comment as I have had this also...but.....but.........Reserve the right to be right in no. 2.