Seems the JS loaded again when entering Grid View (check console):
Uncaught Error: Backbone.history has already been started
thanks for reporting.
I had a look at it, and it seems this is an issue with WordPress core. I just created a ticket on Trac.
I will look into this within the next two weeks or so.
Restrict asset provisioning to pages it is needed. #249
Provide MLP assets files where needed (now). #249
while my Trac ticket is waiting to get merged (and eventually released), I fixed the asset loading in MLP.
Fixed in MultilingualPress v2.5.1.