Navbar expands without animation when .navbar-btn is clicked the first time

[nextgenthemes]

Firefox 13 here on resized browser width for usual navbar like in http://twitter.github.com/bootstrap/examples/fluid.html or anywhere else

when i load the page the first time and click the bottom to expand the navbar, it just gets expanded without any animation, after that i can close and open it and its animates smoothly, as soon i reload the page the issue reproduces.

[mdo]

For some reason Firefox isn't obeying the -moz-transition declaration. Works fine in Chrome.

@fat The CSS is there, and this works in Chrome, any idea if something in FF has changed?

[mdo]

Be sure to include .collapse as well. Was already another issue for that.