Indeed there is a bug in the RadFormDecorator related to IE7/8 and RadInputs (i.e. RadDatePicker, RadTextBox and some other). It has been fixed so you can use the latest internal builds
for development. With the official Q3 2012 version a workaround is to set EnableRoundedCorners
the Telerik team
Explore the entire set of ASP.NET AJAX controls we offer here
and browse the myriad online demos
to learn more about the components and the features they incorporate.