Indeed, the seed restoration worked in the latest version ( 1.8 ) but of course I've lost all the customizations/notes of the original wallet 
We probably need to make more regression tests between versions so upgrades don't break existing client data.
Thanks for the help.
We probably need to make more regression tests between versions so upgrades don't break existing client data.
Thanks for the help.
I recommend you to backup your electrum.dat file before updating if you have set important labels and have imported keys. You can also use the plugin to keep your labels in the cloud, so you'll never lose it.