We found we've introduced a glitch in the new skinning model of RadUpload in the RadControls Q2 2008 (Telerik.Web.UI v 2008.2.723) package.
The browse dialog box does not open when you click the Select button. This happens when one of the parent elements of RadUpload is absolutely/relatively positioned.
The file input is not positioned properly when a parent element of RadUpload is absolutely/relatively positioned.
If the application design allows that, remove the relative/absolute positioning of the RadUpload parent element. If not, attached is the trial fix. Please, open a formal support ticket and ask for the fix to obtain a dev version.
*EDIT*: Attached is the latest build which contains additional fixes of the problem with FieldSet, ModulPopupExtender and RadProgressArea not showing in custom monitoring scenario.