The control is misplaced if it's inside a GridRow/Column and there's the browser zoom is different than 100%.

The fix will be available in the Q1 2015 Official Release.

SetProperty fails on HtmlPresenter.

"Value does not fall withing the expected range" exception is thrown when displayed in a tooltip in a RadMap

RadHtmlPlaceholder does not respect the EnableAutoZoom property.

Does not display properly when placed in StackPanel.

The control doesn't work in Safari

When placed in a horizontal PanelBar, the HtmlPlaceholder is not rendered.

The HtmlPlaceholde does not respect the applied Scale Transformations.

MouseWheel does not work when setting an HtmlSource.

Reason for declination: 
The feedback item is declined due to duplication with the one below:
http://feedback.telerik.com/Project/143/Feedback/Details/112811-htmlplaceholder-mousewheel-does-not-work-when-setting-an-htmlsource
Please follow it instead.  

When placed in scrollviewer and browser is resized in order to appear the scrollbar, HTMLPlaceHodler doesn`t render correctly. The issue can be reproduced in both scenarios - setting the HtmlSource or SourceUrl property.