Many of us on newfoundland are having the problem that when we switch zones chat resets, and guild chat disappears entirely, regardless of whether we go back to the home zone or not. Strangely, guild officer chat does come back; it's just guild chat. The only solution is to reload the game. This is now happening to most of us in our guild 2-3 times a day. It's very annoying. We thought it was just in our guild, but there's been discussion in the help tabs about it from members of other guilds.
I don't know if it's related, but sometimes when I log in there is no guild membership information next to the names of players in the general and trade tabs, either. Again, refreshing the game is required.
Both of these behaviors are somewhat new-ish; the missing guild tab is since the easter event, but the missing membership info has been going for some months now.