Find and Replace plugin - need regex help!

I’ve installed Low’s find and replace plugin and experienced success in removing divs with images and captions. I recently added a new parameter to the regex and, for some reason, it won’t take. Here’s my code:

{exp:html_strip keep="strong,em,p,h2,ul,ol,li,a,div"}{exp:replace find="<div class=QUOTEimagerightQUOTE.*?div>|<div class=QUOTEimagecenterQUOTE.*?div>|<div class=QUOTEimageleftQUOTE.*?div>|<div class=QUOTEarticlesideQUOTE.*?div>" replace="" regex="yes" multiple="yes"}{article_body}{/exp:replace}{/exp:html_strip}

It is the “articleside” div that refuses to be removed. Inside that div are p, h2, and ul tags, but I don’t see how that makes a difference. I’ve tried removing the html_strip plugin as well as putting it inside the exp:replace, but neither have produced any difference.

Any ideas?? Thank you so much!