Redsn0w 0.9.7b5 released fixes Bluetooth issues on untethered 4.2.1 jailbreak
The fifth beta is now available (testers ONLY please!). Bluetooth is now working (and any sandbox-related issues should be resolved too). Please do not pirate the 4.2b3 IPSW! Only those enrolled in the iPhone Developer program have legitimate access to that IPSW.
There is actually a Windows version of beta5, but it’s excruciatingly slow compared to the Mac version because it’s forced to use files on your hard drive instead of RAM while it’s processing the very large IPSW images. It really is very very painfully slow, so we probably won’t be releasing it for testing purposes unless it can be sped up somehow.