Download this level (requires the Beton Night tileset) and attempt to get into the bottom room with Lori or especially Jazz. (Also, enjoy your very small preview of a ground force pack.)

It's an attempt at an anti-Jazz system which is easy to get through (like the one used in older versions of Survivor) and also not susceptible to crashes in unpatched JJ2 (like the new one). I'd like to be able to test it myself, of course, but I'm too lazy to install TSF again.

If it turns out you can get through by sidekicking with Lori, I know a really easy fix, but I'd rather not add something redundant.