PS3 System Software 4.81 and their previous update, today Greek PlayStation 3 developers ErMaK86 (@ermak) and @Echo6Vi updated to XMB Lock 2.04 for PS3 CFW users seeking to lock and secure their console's XrossMediaBar (XMB).
Download: XMBLOCK_v2.04.pkg (58.4 MB)
Below is a rough translation from their Blog, to quote: Greeks return ... XMBLock 2.04 from Ermak86
Another upgrade to version v2.04 XMBLock by our Ermak86, which adds the new Custom Firmware 4.81. With this PKG now you can lock the system update the system settings and network settings for security reasons to not change a setting that should not even if someone presses format from the system settings.
Stay at PSJailbreak.gr with more to come...