If you are using or are thinking about installing Office 2007 a list of known issues can be found at http://officebeta.iponet.net/en-us/products/FX101517941033.aspx.

If you don't have Office 2007 installed, you'll need an active x control installed. You can get the control from http://www.microsoft.com/office/preview/beta/deploy.mspx.