There is no way to downgrade to iOS 4.x.x as apple has stopped signing the software.
You can only downgrade it if you have your 4.3.X SHSH blobs. If you don't, there is no way back.
i'll just have to wait for the release of jailbreak for ios 4.3.5,
There won't ever be a 4.3.5 jailbreak for the iPad 2. The next jailbreakable version is going to be 5.0.
You might as well upgrade to 5.0 and do a tethered JB. Google it.
You might as well upgrade to 5.0 and do a tethered JB. Google it.