If you create a slider without value or with one of min or max 0 it will not register an events. You cannot drag the handler.
will lead to the same result.
The solution is to start from a value different from 0 and if you need to set the value to 0 to do it with a small value close to it - like 0.001 , but this is not good :)
This is fixed in iPhone mobile SDK 1.4
I know, but thanks anyway :)
@Damien I reported before being fixed.