ok, started from scratch. I installed the jenkins 2.19.1 using the suggest plugins during installation. After that I installed active choices plugin and built my demo project. As expected it worked. Then I only installed jQuery plugin + restarted jenkins service and the sample stopped working. Disabling the jQuery plugin and restart jenkins service it works again.
At this point I started from scratch again. This time I didn't install any plugins during jenkins installation routine. After installation I just added active choices plugin (including the plugins it obviously depends on), restarted and my example project worked. Then I just installed jquery (and its depending plugins) , restarted and it didn't work anymore.
The host in this sandbox environment was a windows 7 32 bit.
Hope this helps you to reproduce it on your side.