Hey Arvin, Yep, this is Dawn.

I bought a 150 Kashmir from REI, but returned it after using it for 1
day because it's a big and stiff board for me and didn't quite like it
at the time.

I ended up buying a 147 NS Infinity, the girly version of the SL.

The board is kinda stiff, not as stiff as the kashmir, but it feels
lightweight and really sensitive to me -- compared to the other boards
I've ridden before -- I had 1 day on the Kashmir, 2 days on the K2 Mix,
several years on the Luna.

It's the sensitivity of the board that made me wonder if the board's is
a possible problem.

Then I read some comment about how a snowboard flex not being right,
going at mach 5, not being able to hold your 120lb weight while
landing... Forgot where I read it though.

When I wash out going fast, it's on the downhill ramp, almost towards
the middle of the ramp.

When I speed check, approach the jump more cautiously, I still end up
on th downhill ramp, but towards the beginning of the downhill ramp.

I don't freak out and physically over rotate my body while trying to
land in an attempt to slow my speed.

Yeah, I'm aware landing on the transition is bad ... And it's when I
go super slow that I end on the flat transition.

Hmmm, it's possible that I could be trying to turn as soon as I try to
land on certain jumps, cause I'm trying to break the speed, I think
that's part of the the problem.

But there are other jumps, it feels like my legs are like jello and
couldn't absorb the force of the landing.