I daresay you've sorted this by now, but if anyone else with a similar problem is reading this, I'd ask: Did you first reattach the rose with incorrect connections, blowing a fuse or tripping the circuit breaker in the process, before correctly rewiring the rose - leaving the light permanently on? If that's the case (and the switched live has at any stage been connected to a neutral feed), then it could be that the power surge has fused the connection at the switch - in which case the switch needs replacing.
Amblonyx, July 2009