Just a little tip for those on REBUG 4.21 or 4.30 versions:
To install REBUG toolbox after updating to a REBUG CFW, scroll to package manager ->install package files->PS3 Hard Disk->Rebug toolbox.pkg.
My preferred REBUG toolbox setup:
XMB operation mode=DEBUG
Debug menu type=CEX QA
If you watch DVDs like I do, you will want to turn on DVD upscaler via the "video settings" in the settings menu on XMB. Take note that "Video settings" will not be available in XMB settings unless your set up is this:
System mode: REBUG
XMB operation mode: RETAIL
Debug menu type: CEX QA
Take note that the Cex QA menu type is unavailable in this mode (usually found below network settings) After adjusting the video settings to your preference, you may revert back to my preferred REBUG toolbox setup (your video settings adjustments will remain) and the Cex Debug menu type will be available again. So u can enable WMA, ATRAC etc...
To members who remain faithful to Kmeaw 3.55 CFW...have no fear, there is no difference in stability and you can always go back using the REBUG 9.99 Downgrader (personaly tried and confirmed)