Looking at: http://github.com/dpp/liftweb/blob/master/lift-base/lift-webkit/src/main/scala/net/liftweb/builtin/snippet/Msgs.scala

The documentation suggests that certain elements (like error_class) can be overridden. But I did it using:

<lift:Msgs>
<lift:error_class>errorBox</lift:error_class>
</lift:Msgs>

I'm guessing that the <lift:snippet type="error_report"> is dated?