Any ideas why <strong> tag doesn't work but CSS does?

<span class="bold">Some Title</span>

.bold
{
    font-weight:bold;
}

This renders boldly, however this:

<strong>Some Title</strong>

Does not. It just renders as regular text. I'm using the HTML5 doctype and the Google font:

<link href='http://fonts.googleapis.com/css?family=Droid+Sans&v2' rel='stylesheet' type='text/css'>

Anyone experienced this as well?

Edit: BoltClock suggested it might be CSS reset, here's the chunk for <strong>

/** CSS Reset **/
html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed, 
figure, figcaption, footer, header, hgroup, 
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
    margin: 0;
    padding: 0;
    border: 0;
    font-size: 100%;
    font: inherit;
    vertical-align: baseline;
}