Portable gaming confusion abounds, as an unnamed Nintendo developer claims that an upcoming game from their stable has been refused release due to "being incompatible with the DSi hardware". The DSi, Nintendo's latest evolution of their handheld system, is supposed to be backward-compatible with all DS games (excluding those which require the GBA slot, as it no longer has one); however the developer is claiming that their new title, fine on the DS, causes system freezes on the DSi.
Nintendo will only reaffirm that all DS games should work fine on new DSi consoles. At this point, it's hard to know whether existing titles will experience problems on the new hardware, which isn't set to launch outside of Japan until 2009.
Even if the existing back-catalog shows no compatibility problems, it's plausible that developers who believed their in-progress games would be compatible with both the old and new systems (which will remain on sale simultaneously) will now have to refettle them to suit the DSi's slightly different hardware. Nintendo's supposed rejection of at least one title would indicate that they won't permit games for just one version of the console.