The unnoficial build of ReActPSN brings us to version 2.23b.A This was created to assist users using Rebug 4.21.2 cfw.A See the developer notes below and check it out.
"After failing to get v2.23 ReActPSN working on 4.30.1 and 4.21.2 Rebug's, I found out that the ReActPSN ELF had hardcoded dev_usb000 paths.
Since my usb path (and I would assume others too, since it's referenced by Rebug themselves) is dev_usb006, ReActPSN wouldn't work.
I have tried this on Rebug 4.21.2 only, but as long as your usb device is named dev_usb006, and your vsh.self is patched, I see no reason this wouldn't work on other 4.x CFW's.
The same issues as with v2.23 remain. I.e. a message that the system was shut down improperly and that it has to repair filesystem after ReActPSN reboots the PS3.
THIS FIX IS FOR 4.x CFW USERS WHOSE USB DEVICE IS NAMED dev_usb006 ONLY!
Of course you install and run this on your own risk. Credits go to the original creators.