'Safely Remove' mounts the Seagate Backup plus drive again and again

I had upgraded my ubuntu to 15.04 recently and while using my Seagate external hard disk, I found there is no Unmount option but a new Safely Remove option is provided. And it is not working properly as it keeps mounting the drive a few seconds later again after I had clicked the Safely Remove.

I found a few answers here and here but those are command line oriented.

I'd like to know if it is a bug or some other issue with my system. And whether the Unmount option can be included again.

Any help appreciated. Thanks.

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