The last part of the version number is the platform version. Silverlight 3 is 1030, Silverlight 4 - 1040, WPF 3.5 - 35, WPF 4.0 - 40. Since the RadUploadHandler.dll is not a Silverlight assembly (it should be referenced in the Web project, not the Silverlight app), its version uses the WPF naming, hence the difference.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items