I've the same problem on my iPad. Seems to be related to the new Jira release that has been deployed the other day.
2013/10/13 Gary Gregory <garydgreg...@gmail.com> > I can't use JIRA on my phone. Pages do not scroll and the mobile view > doesn't include attachments! WTF! > > > Sent via the Samsung Galaxy NoteĀ® 3, an AT&T 4G LTE smartphone