Some references to skin resource files are hardcoded in Telerik.Web.UI.dll and don't depend of the web.config/appSetting "Telerik.Web.SkinsAssembly". The result is when you use a custom Skins Assembly and a Telerik control uses these hardcoded references on resource files, these resource files are not displayed because Telerik.Web.UI.dll is searching a resource file for a control as "Telerik.Web.UI.Skins.<Skin Name>.<Control>.<Resource filename>" and not as expected "<Skin Assembly Name>.<Skin Name>.<Control>.<Resource filename>.

It happens in the following controls:
- RadGrid: Only the column GridEditCommandColumn ButtonType="ImageButton" gives a invalid references on resource files for Edit.gif, Update.gif, Cancel.gif.
- RadDataPager: Images of SEO buttons, like PagingFirst.gif, etc.

The requested fix: to test if web.config/appSettings "Telerik.Web.SkinsAssembly" is available and not empty, and if yes, to use its value in place of the hardcoded "Telerik.Web.UI.Skins.dll".