Incompatibility FTW

Toward the end of a marathon repair session spanning two days at the shop I ended up with an early 2000's GT cross bike in my stand. Very vague work order: "Adjust front derailleur, if you can't get the full gear range adjust so the lower ones work." Strange because it seemed that it was the rear derailleur that was out of whack with a super loose cable. Plus it was a double. Not much range with a double, it's either high or low. Well, the new employee checked this one in, maybe he hit the wrong check box. I decided to check the both of them. How long could this take? I get a few minutes in and things are not coming together well, so I do a bit of counting. 8 speed cassette, 9 speed STI shifter. Are you serious? I get a sinking feeling that this is somehow a shop screw up, as it was purchased here. I comment to a co-worker and check the short repair history we have on file. This problem has been noted before but not fixed? Very strange. A-train, the co-worker mentions something about when 9 speed was new, bikes shipping with 8 speed cassettes. Now I'm coming back. I barely remember this problem. I can't believe this bike left the shop like this. So I'm grasping for straws, this was sort of a shop screwup, but warranty an 8 year old bike from a manufacturer that's been bankrupt/sold a couple of times since this catastrophe? Good luck. So I try the long shot: Sheldon Brown's alternative cable routing for inter-compatibility of older Dura Ace parts. It worked perfectly from the moment I cinched down the bolt. I was shocked, and it was glorious.