One of my two Gnome terminal windows (that I regularly keep around for initiating PPP sessions, running telnet, etc.) lost the ability to copy text. I could select text in it fine, but the selected text would "go" nowhere, i.e. not into the Gnome buffer (Emacs "kill ring" is another term for that sort of thing). Using Paste (mouse button two, or menu item) would paste whatever some other window -- even the other Gnome term window -- had most recently copied. No idea how this came about. I've been using two terms as part of my Gnome session (defaulting to whatever RH 6.2 installs; Enlightenment, I gather?) for months and have frequently used copy-and-paste in that second window, but I've never seen this before. Strange that something so basic could be lost track of.
Works for me in more recent releases.