Comment 43 for bug 1091792

I bought a second hand hdd from ebay that had previously been in a sky box. I gave it a good formatting and then installed elementary freya on it and ran update. My old hdd is still in but is full, so I have dual boot same opsys. I am getting this exact bug. I have a fat32 partition on the old hdd for storage/ backup and never had any problems before but now it's a real hassle to boot into the second hard drive because of this bug.
update grub gives me this mess

[sudo] password for sapa:
Generating grub configuration file ...
Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported.
Found linux image: /boot/vmlinuz-4.4.0-93-generic
Found initrd image: /boot/initrd.img-4.4.0-93-generic
Found linux image: /boot/vmlinuz-4.4.0-92-generic
Found initrd image: /boot/initrd.img-4.4.0-92-generic
Found linux image: /boot/vmlinuz-3.19.0-80-generic
Found initrd image: /boot/initrd.img-3.19.0-80-generic
Found linux image: /boot/vmlinuz-3.19.0-26-generic
Found initrd image: /boot/initrd.img-3.19.0-26-generic
Found elementary OS Freya (0.3.2) on /dev/sda1
done
sda is the old drive, the new one is sdb1 with some linux swap space.
It tries to mount a non-existing /tmp on every boot into the new drive, is completely ok when booting into the old drive.