Well the best way to get it right the first time is use firefox and install firebug. I had to fo most of my theme that way as the stylvar was way pre-mature.
thanks charlie, that helped so much. from firebug I can see that border is set by CSS "section"
which isn't in the style var editor but looking in the CSS templates I found this chuck of code in vbulletin-formcontrols.css
HTML Code:
/* div.section is needed to resolve IE7 percentage width bug */
.formcontrols .section {
padding:0 15px;
}
I added my border color & width there & it worked like a charm. I guess I better check IE now. maybe I need to set it in both places.