I came across this thread in case you are seeing breaks in some telerik controls in IE 8 as well.
Some of the comments mention using a compatability meta tag and placing it as the first meta tag:
< meta equiv="X-UA-Compatible" content="IE=7">
For more info please check out the thread at:
http://www.telerik.com/community/forums/thread/b311D-bcgamd.aspx
If you have any more tips, tricks, etc please email them to susan@clinchportal.com