DevkitPro had a few component updates. One of those updates is for libNDS.

Release notes:

Just another quick maintenance release, fixed a typo in oamSetMosaicSub & changed the fifo sync code a little. The cpu synchronisation code wasn’t working under some circumstances on hardware and happily the fix for this also got code working on no$gba 2.6 again.

http://forum.gbadev.org/viewtopic.php?t=16739