I have a glitch with the mobile site. Not sure if it is "interesting" but I will post here nonetheless.
Flight 1191 today (TPA-EWR, 4/8/2012) is showing "Full" in both coach and first on the mobile site. But, regular united.com is still selling coach seats.
When the mobile site is saying Full, I thought that meant there weren't any more seats for sale (unless I don't understand the definition of Full).