Couple things:
1) Like I said, I did my reaction at -50. I don't know whether this is substrate specific or not, but I was following one of Sharpless' procedures (a JOC article or something similar, it was a long paper). After that, I left it overnight in the freezer.
2) I used tert-butyl hydroperoxide. I don't have experience with cumene hydroperoxide so I don't know the relative reactivities, but you may consider using that instead as well.
3) We did have a solvent drying system, and if I'm not mistaken I was using DCM, not toluene (but it's been a while so I may be off on this).
Let me go back through my notes and see if I can dig up that Sharpless paper, that will clear a lot of this up I think.