In GlotPress, you may need to export 3.3.x/ms strings and import them into dev.
For 3.4, we’re changing how we split strings into multiple pot files. Since 3.0, we’ve done a generic POT and then a second POT for multisite. We are now going to be doing a frontend POT, an admin POT, and a network admin POT. The projects have been added to GlotPress here and here.
While merging and splitting projects in GlotPress, some strings got orphaned. Before you go re-translate all of the missing strings, first go to translate.wordpress.org/projects/wp/3.3.x/ms, export a po file, and import it into both wp/dev/admin and wp/dev/admin/network. Everything should be back to normal.
Cheers, and sorry for the trouble. For more, see ticket 19852.