Attached bones won't move with mesh

I’m using 3ds max 2010 and I followed mariokart64n’s tut. Everything was working until I moved the animation bar back to 0.
http://img709.imageshack.us/i/pic1og.jpg/
http://img35.imageshack.us/i/pic2nu.jpg/
As you can see in the second picture, the envelopes don’t move with the mesh. It moved before, but now it isn’t. I also tried saving and opening the file again, but it doesn’t fix the problem. Anyone know what’s wrong?

go into the mesh modifier, select all vertexes or something, deselect them, click on the whole mesh modifier, then click on the skin modifier.

There’s definitely a better way to do this (though don’t know about it) but it always fixes the issue for me.