Mysterious local server issue (running locomotive on osx)

Hello:

I’m new to RoR and have run into an issue that I can’t find in any faq.
I was following through a guidebook project implementing some ajax
effects when I tested a link to edit a row and the application seemed to
freeze (page didn’t load, though browser did not crash). The weird part
is that without changing any code I could not no longer load the index
page on my local server that I had accessed 30 seconds previously. I
restarted my webserver (locomotive on osx) as well as mysql server, but
I still couldn’t load http://localhost:3000/. I also tried a $ rake
tmp:sessions:clear command. Any further ideas?

Thanks,

Peter