A div is a block-level element, so the browser is behaving correctly in this instance. If you want to have this occur inline, then you must use an inline-element such as a span, for example: Some text<[b]span[/b] class="ex" title=""><a href="red-widgets/">Red widgets</a><[b]/span[/b]>some text.
Of course, it may not be necessary to add the extra
span at all - have you tried applying the styles directly to the anchor itself? Some text <a [b]class="ex"[/b] href="red-widgets/">Red widgets</a> some text.