Using portable devices with Windows Vista Home Premium

I have installed Windows Vista Home Premium. When installing from scratch the
internal DVD/CD drive is properly installed and working, as are all other
devices. But from time to time the DVD/CD simply disappears from the system.
Last time : it was changed in a removable disk. I think it has to do with
using my Nokia E61i als an external hard disk. The same happens when using my
iPod (Classics with iTunes last version) as an external hard disk. Each time
the DVD/CD disappears definitely from the system. The device manager notes
that the device 'cannot be started (code 10)'.

Anyone knows what is happening ?
Thanks
Chodko