Problem with PO/MO in new version — labels but revert to English after saving

Hello there!

Previous versions worked like a charm using a custom PO/MO in pt_BR located inside my theme. After updating today (using AIO) things changed on MBCustomPostType extension (I really was fond of the previous interface) — and now my pt-BR translation is gone for good.

But the worst part is — no matter what label I change while creating a CPT or taxonomy, they always revert back to English.

What I was doing — just before "boot" the MetaBox stuff, in my functions.php, I was calling my PO/MOs for the extensions I use:

load_textdomain( 'meta-box', MY_PATH.'/languages/plugins/meta-box-'.get_locale().'.mo' );
load_textdomain( 'mb-custom-post-type', MY_PATH.'/languages/plugins/mb-custom-post-type-'.get_locale().'.mo' );
(...)

What should I do now? Is it a matter of calling a new PO/MO? Perhaps my old PO/MOs are not up to date?

Thank you!
G.