Slow/poor responsiveness in org files

[Tim Cross]

About a week or so ago, I updated emacs from bzr and saw that org 7.7
had been merged in. Since then, I have also noticed a distinct delay
when performing various editing operations within org files. For
example, killing a line wiht C-k in an org mode buffer is taking about
4 seconds!

I updated emacs and tried again with emacs -Q and got the same result

My version is 24.0.50 bzr relno 105475

Has anyone else seen this? What would be the best way to debug this
sort of issue, emacs profiler?

Tim