Improve copy-pasting of furigana

Question

I have the following markup:

<ruby><rb>ネックスス</rb><rp>［</rp><rt>Ｎｅｘｕｓ</rt><rp>］</rp></ruby>

It renders very nicely in Chrome and IE (gasp!) and makes correct use of the fallback rendering in Firefox (not that it has any choice in the matter, just ignoring the unknown tags is how the fallback works).

However, I have noticed that IE and Chrome do not factor in the <rp> elements when copying the text to the clipboard. Attempting to copy it should result in ネックスス［Ｎｅｘｕｓ］, but instead yields the parentheses-less ネックススＮｅｘｕｓ, somewhat defeating the purpose of furigana (imagine how that would look in a more "usual" situation of having kanji as the base and kana as the furi...)

Is there any way I can fix this, or is this a browser issue?