By only using li[@data-item-type='tweet'] sometimes void entries where
selected, and in particular the ones under <ol class="activity-popup-users">.
So just pick the items under <ol id="stream-items-id"> as the actual tweets
with valid contents in them.
                         <xsl:value-of select="//a[contains(@class, 'profile-picture media-thumbnail')]/@href"/>
                     </url>
                 </image>
                         <xsl:value-of select="//a[contains(@class, 'profile-picture media-thumbnail')]/@href"/>
                     </url>
                 </image>
-                <xsl:apply-templates select="//li[@data-item-type='tweet']"/>
+                <xsl:apply-templates select="//ol[@id='stream-items-id']/li[@data-item-type='tweet']"/>
             </channel>
         </rss>
     </xsl:template>
             </channel>
         </rss>
     </xsl:template>