it could have been because you needed to refresh your browser
today i notice that the battle arena tab was missing on my page and i refreshed and it was there
you should be able to go in and out of DEF but you loose 5 mins
if you came out of DEF and there was time left you should be able to go back in
if you were unable to go back in and there was no waiting time left it could be a glych
i sugggest emailing support with the details and if you have a screen shot send in as well but i would contact them to see what happend
Last edited: Nov 27, 2012