Hi Bryan,
yes, thanks for the report.
that setting there has, in effect, been deprecated. The class for the buttons is set globally, in the WebServer procedure, on the Buttons tab.
They can also be over-ridden in the procedure, but at this time only in source code. eg
p_web.site.nextbutton.class = "myClass"
A complete list of the button names is in netweb.inc.
and indeed a complete list of their properties is there as well.
Cheers
Bruce