Dead keys not working in Emacs-Lisp mode *only*

Question

I've been having a really annoying bug when editing elisp files recently: dead keys do not work, but only when I am in Emacs-Lisp mode. If I type a key that is configured as a dead key (say, '), I get a prompt that says Emacs-Lisp: on my mini buffer. Then, typing any normal letter gives me the corresponding accented character (say, á), but hitting SPC, which should give me the single quote character ', does nothing instead. Deactivating Emacs-Lisp mode and going into fundamental mode solves the issue. Does anyone know how to fix this?

Just a disclaimer: some people (including myself) were affected a while ago by a seemingly similar issue that required them to explicitly require iso-transl to get dead keys. I've already done this, and it did fix most of my problems with dead keys, but this weird issue in Emacs-Lisp mode appeared afterwards.

Edit:

If I don't require iso-transl (or do emacs -q) then the problem changes: I get undefined dead keys, just like I did before, but they don't bring up the Emacs-Lisp: prompt on my mini buffer. If I do e.g. C-h k <dead-acute>, then the Emacs-Lisp: prompt comes up and no help gets shown, except that if I try to type <dead-acute> several times and then hit C-g the following slightly different message pops up:

<dead-acute> C-g (translated from <dead-acute> <dead-acute> <dead-acute> C-g) is undefined

I'm running Emacs 24.3.1 on Ubuntu 14.04. I think before I had it compiled from source and it was giving me the same problem, but I can't quite remember.

Edit 2

If I do (describe-key [dead-acute]), Emacs says that it is undefined. If I try this trick to find where the key is bound, it still shows me the Emacs-Lisp: prompt as above, except that if I hit C-g right after I get

At Point: (nil nil nil nil)
Minor-mode: 
Local: 1
Global: 1

This is different from the message it prints for C-g on its own. If I try to do the same on a different mode, I need to press SPC after <dead-acute> to get an answer

At Point: (nil nil nil nil)
Minor-mode: 
Local: 
Global: self-insert-command