Apparently, the new version of emerge uses the window's title line to display status information during merging, when run under X11. My problem is that emerge seems to reset the window title to "xterm" when it's done -- no matter what the window used to be called before! This is certainly not a major problem, but I personally find it annoying because I use "named windows" all the time, to keep track of where I'm logged into what machine and as which user. IMHO, emerge should either re-set the exact title that used to be set before emerge was called, or it should not mess with the window titles AT ALL.
maybe belongs to bug #21430
If you set that form the prompt, you shouldn't be having a problem. Setting the title back to it's original form is not trivial, as I've discovered... I'd either have to use Xlib or a fairly large hack. If it's a problem, set FEATURES=notitles
theres a patch at Bug 22664
*** This bug has been marked as a duplicate of 22664 ***