Sony's incentive programme to entice existing PSP owners to upgrade to the new PSPgo by offering three free downloadable games has already hit a technical hurdle.The incentive programme - as previously detailed by Game Console - allows owners of older models of PSPs to download three games free of charge in order to entice them to the newer PSPgo, which no longer supports Universal Media Discs (UMD).According to Engadget, non-US users are encountering an error by the name of 80109D53, which is preventing the downloaded titles from playing on a PSPgo. Sony is aware of the hiccup and working towards a fix for affected units. In the meantime, users can reportedly avoid the problem by downloading the free titles directly to their PSPgo as opposed to transferring them from a PlayStation 3 console.