Sounds like the pressure plate is not fulling disengaging and is keeping the clutch and gears spinning even though the pedal is pushed all the way in. I don't know what causes it but it does occur on SVTs occasionally. Try bleeding the clucth. It could be clutch junk buildup binding between the clutch and pressure plate if the clutch is on its way out.
I had this issue on my last car and a new clutch solved it, though I'm not saying it is your problem.


Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black