Hello Eric,
We do not claim that RadControls for ASP.NET AJAX pass CSS validation, only XHTML compliance. The problem is that older browsers (namely IE6/7) have bugs (like the hasLayout bug), do not support many of the modern browser features and also some modern browsers had chosen to introduce new CSS features as proprietary CSS properties (-webkit-something, -moz-something, etc.). To ensure matching cross-browser functionality in all our controls, we are forced to forfeit CSS validation. I hope this is not much of a problem for you.
Best wishes,
Kamen Bundev
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Explore the
Telerik Public Issue Tracking
system and vote to affect the priority of the items.