Cannot copy from sent messages using 'Ctrl-C' in Empathy

This looks like bug 665552. I recommend you visit that bug page, see if the description and comments are consistent with what you've experienced, and if so, indicate that the bug affects you, using the green "This bug affects..." link near the top of the bug page. You may also want to subscribe to that bug, so you receive email notifications when its status changes (for example, when it's fixed, or when an experimental fix is available for you to try should you so choose) and when comments are posted in it.

Since the bug was thought to have been fixed but is recently discovered actually *not* to have been fixed, it would be a good idea if you could any missing information in the bug report (by adding a comment, *not* by editing the bug report). In particular, I recommend you post the full package version for the empathy package installed on your system (this might contain letters, and you can find it in the Software Center, Synaptic Package Manager, or by running the command "apt-cache policy empathy" in the Terminal) and whether or not Ctrl+V works for pasting. (It would be good to rule out the possibility that the problem is with Ctrl+V rather than Ctrl+C, since most of the time when people copy by right-clicking and clicking Copy they paste by right-clicking and clicking Paste, and when people copy by pressing Ctrl+C they paste by pressing Ctrl+V.)

If you find that this substantially impacts your productivity or the enjoyability of your instant messaging experience, you might consider temporarily switching to another instant messaging client, such as Pidgin, as a workaround.