0.23 changed my spaceplane somehow

[SofusRud]

before 0.23 i built this SSTO shuttle for my upcoming Laythe mission. It a three person thing with a Mk-3 cockpit, a turbojet and two 48-7s engines. I was quite happy with it and it did all it had to reliably.

Since the update however, something weird is happening on takeoff. As it pics up speed, it becomes unstable and crashes. Note that this is not the usual "veer to the side and crash" thing that we've all experienced when our landing gear wasn't parallel. As it hits around 60-70 m/s, it starts bouncing from side to side, each bounce becoming bigger and bigger until it flips. This happens regardless of whether SAS is on and i even tried switching out the tubojet and the rockets for a RAPIER, which didn't work either. I have never experienced this before, neither with this plane or any other.

Can anyone help shed some light on this issue? I am quite proud of the plane and would hate to have to can it.

here is the craft file: https://www.dropbox.com/home/KSP%20share

[Kasuha]

Command pods now have monopropellant in them and they are heavier by the weight of this monopropellant. For instance Mk1-2 command pod now weighs 4.12 t instead of 4 t.

You can tweak its monopropellant to 0 in VAB/SPH.

[SofusRud]

Command pods now have monopropellant in them and they are heavier by the weight of this monopropellant. For instance Mk1-2 command pod now weighs 4.12 t instead of 4 t.

You can tweak its monopropellant to 0 in VAB/SPH.

how does that explain the whole "bouncing issue?

[antbin]

Sounds like 'wheelbarrowing'. The heavier nose means only the back two wheels are lifting off the runway.