Please describe the problem:
Using a prompt which sets the window title causes very slow updates, cursor
jumpiness.

Steps to reproduce:
1. Open gnome-terminal and run bash 3.1.17.
2. export PS1='\[\e]2;\u@\h: \w\a\]$ '
3. Type some text, or paste some with middle-click.


Actual results:
After every character, the cursor returns to the beginning of the line, and then
back to the correct place, taking a significant fraction of a second.  Pasting a
line of text can take several seconds.  During this time, the CPU is nearly idle.

Expected results:
I would expect the cursor to move with the text, and pasting to be instantaneous
as it always has been.

Does this happen every time?
Yes.

Other information:
This may be a bug in bash; it began occurring when I upgraded from Ubuntu Breezy
to Ubuntu Dapper Beta, so lots of packages have changed.