Is EasyPG ready for Gnus?

[XeCycle]

Hello, I read in the manual that PGG is deprecated in favour of EasyPG
for OpenPGP encrypting and signing.  But I can't get it working with
EasyPG.  With `(require 'epa)' and `(require 'epg-config)' in my
.gnus.el, it shows some debug info like "wrong number of arguments" when
reading a signed message.  I changed them to `(require 'pgg)' and
`(mml2015-use 'pgg)', and it works.  

Should I update my Emacs?  It looks like a bug.  I'm using Emacs from
Archlinux extra repo, its version is 23.3.

Thank you.

-- 
Carl Lei (XeCycle)
Department of Physics, Shanghai Jiao Tong University
OpenPGP public key: 7795E591
Fingerprint: 1FB6 7F1F D45D F681 C845 27F7 8D71 8EC4 7795 E591