pattonto: The problem if you use the quick reply is that you can't read the threads.
Yes. There's another workaround for that. What I do is, I open the thread in a new browser tab and keep the main threads overview page open in the original browser tab. So, I read the delivered PM in its own browser tab, but when I need to reply to it, I switch to the original browser tab with the messages overview, and click the "Quick Reply" arrow there.
What I also do often, is I read the PM in the email delivered to me, and reply to it from the threads overview page. I can always look in the email message if I need to consult the text of the PM I'm replying to.
Another problem with PMs is that, unlike here in the forums, the Quote button, for some reason, isn't available when replying to a PM, although it would definitely be useful.
Also, there seems to be no way to send a PM to more than 1 player (or if there is, please let me know how to do that).
Lots of bugs all around the PMs feature, as can be seen.