The stock Vista driver should work fine.
If it's a USB external drive, try other ports. If that doesn't help, check the device manager to see if there are any conflicsts. If there isn't, expand the universal serial bus controllers, and uninstall all of the USB root hubs, then restart. They'll reinstall on restart.
If none of that helps, run this Fixit scan.http://support.microsoft.com/gp/cd_dvd_drive_problems