While you wait, you could run in Firefox with Firebug installed. The FAQ "My Ajax stopped working" has the first answer "A browser will often decline to run any Javascript after an error". So trap the error and you might just solve it yourself.
If you do, please remember to finish your own thread, so the archives won't have a false trail!
I'm no guru, but I had a similar problem once so maybe my experience
will be helpful.
This was a while back, and I'm barely awake yet, so forgive my
vagueness.
In my situation, the JS in the partial was setting up some structures,
lets say a sortable list, but there was a single line of javascript at
the end of the page which "turned on" all the objects. When reloading a
partial, all the setup code got re-done, but the code outside the
partial was of course not re-loaded, so the objects remained inert.