Try thinking about doing two 360s, rather than a 540 and another 180. Sounds to me like maybe you're doing the five, then trying to pull it around, and that's where you're going off-balance. If I stall at any time during a 7, it's after the first 360... then after that, the last 3 is pretty fast. Try going bigger and spinning faster, getting comfortable with the rotation... you'll stomp it sooner or later.
KAMIKAZE: MAKING NS MORE CORRUPT ONE THREAD AT A TIME
*Proud member of Newschoolers for Peace*