^exactly, still may need an adjustment and its easy to check.

You said you checked the shifter linkage... how did you accomplish that?
I mean you can go to the arms off the transmission and manually change the gears but did you have someone sit in the car (car off), push the clutch pedal down and shift through the gears to actually see if the shifter arms are moving and going into gears? If you didn't I suggest you do because anyone can manually change it at the transmission but that doesn't mean the shifter linkages are working.