So, here is now what happens.
I made a back up of my module, and deleted it.
I created a fresh one, named it the same as the original and set it to be used in my campaign.
Saved it, exited the TS and reopened.
I ended up with a temp1temp1 module.
Something in the campaign folder is preventing the modules associated with it to be opened it seems. I'm starting to consider a new install and recopying my last backup, just in case something went wrong during the copy paste madness.
Edit: Good news, is that it's not my campaign related. I created a test campaign, and linked a test module on it. Now, that one normally opened as a separate module. But now that it is in a campaign it gives a temp1 as well.
Scratch that. Created another one and now it opened ... Is it random or what ?