6.4 code splitting problem

I don’t remember how i managed to get it working, but, it was definitely working. How do i get it working back again?
I think i had a version of 6.4 that had code splitting enabled by default and it was working like a charm.

EDIT: i would gladly use the 6.4 version that did this, if i could find it. The way to enable lazy loading with the custom widgest.gwt.xml still loads up to 500K in total, that version was even splitting the css or something, inlining it to each control. It still loads ~200K even with cache on! I swear it was loading only 24K instead of 600K for my whole front end when loading initially!

I had FF’s web developer plugin with cache disabled when i was testing it.
Either was the initial payload gone, and code splitting was working, or FF’s Firebug plugin had a fluke and wasn’t registering the payload request, it only was registering a small payload, relevant to the controls i was loading (which makes sense).
It even felt faster.

Something must’ve gone wrong with Firebug, otherwise i can’t explain, 24K doesn’t seem a reasonable amount if you think about it. Tried a few nighly builds and can’t find the one with code splitting enabled by default.