How long are you garaging the beads in the kiln before you start the annealing/ramp down? When i'm working with Rubino, especially with beads that are mostly rubino, I have to make sure I make those beads LAST so they don't get as much "soak" time or they will keep striking. I have had them go to an almost opaque purple orchid color if they sit in the kiln too long - very pretty, but if you want a pure pink transparent look, not good.
You also might try to only work your rubino as LITTLE as possible. If you're doing rubino flowers or dots, make sure that is the last color you add to your beads and then just heat enough to melt in and then be done with the bead. If it doesn't strike all the way in the flame, that's ok - it will strike in the kiln.
Make sure you're working fairly cool with the propane turned way down also.
Hope this helps a little.