I'm having the same problem and I quite don't understand why it isn't working.
<ArticleRowTpl> working:
[[+tv.articlePreview:notempty=`<img src="[[+tv.articlePreview]]" class="img-right" alt="[[+pagetitle]]" />`]]
<ArticlesLatestPostTpl> not working:
[[+tv.articlePreview:notempty=`<img src="[[+tv.articlePreview]]" class="img-responsive" alt="[[+pagetitle]]" />`]]
No magic, quite plain, no difference, just another CSS class. It took time to get first working also, I don't know what made the difference in the end, but as quoted it is working.
TV config in Articles page are both set to Yes with an empty list, TV is available on all templates (also problem occurs on the same page, Articles list has the Latest sidebar as well).
Thanx