R4i-SDHC Firmware was updated to V1.53b by r4i-sdhc.com on 15th Feb , 2012. please see the below Change Log about R4i SDHC Kerenl V1.53b

Change Log (R4i SDHC V1.53b)
1.Support 3DS V3.0.0-6Please goto “setting/upgrade” to upgrade frimware.
2. Fix recreate save file issues due to NDS filename big/small capital letter problem.
3. Improve unkown new games loading routine (to avoid errcode=-4 problem).
4. New hints screen, presss “START” to view hints.
5. Solved games:
   5962 – Metal Beyblade 2: Big Bang Bladers (KR)
   5960 – Live-On Card Live-R DS (KR)
   5959 – Jeongukmin Model Audition Superstar DS (KR)
   5957 – Tropical Lost Island (v1.1) (EU)
   5953 – Professor Layton and the Spectre’s Call (EU)
   5934- Call of Duty: Black Ops (EU)
   5930- Tinkerbell – 2 Disney Games (EU)
   5597- ATARI Greatest Hits: Volume 2 (US)

Download: R4i-SDHC Firmware V1.53b