Welcome to the forums montyw,
You can go back to a previous firmware version, e.g. 1.04. Downgrading of a firmware version is done in the same way as upgrading. Please try if that solves your problem. It could also be a problem related to your system. To check if the drive it at fault you can run a self-diagnostics test. To read more on this please check out the FAQ. Report back with your findings so we can assist you further if needed.