From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030703
Description of problem:
This bad behavior has existed in Rawhide gnome-terminal for a while now after
RH9. RH9 did not behave in this way.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Scroll thousands of lines in gnome-terminal.
2. Click and hold from the bottom.
3. Attempt to highlight the entire scrollback buffer by moving mouse up.
Sometimes one line repeats drawing on the screen until the entire window is
full, then it continues to draw normally.
Should scroll normally.
gnome-terminal-2.6.0-2 seems to have fixed this.