On Friday, Apple seeded "Mavericks Preview 3 Graphics Update 1.0" to developers. The update came just four days after Apple released OS X Mavericks Developer Preview 3 and then followed that up three days later with another seed fixing an OS X Recovery bug.
The "Mavericks Preview 3 Graphics Update 1.0" issued on Friday fixes a second known bug with OS X Mavericks Developer Preview 3 that caused Macs running the build to reboot without warning. But unless you're a developer, fear not about any of these bugs. Hopefully they'll all be ironed out for good when OS X Mavericks ships in the fall.