Hi guys. I have Iphone 3G with OS 4.0.1 installed ,jailbreak-ed and unlocked and SHSH saved in Cydia. But because OS 4.0 have slowed down my phone really badly I was wondering if there is a way to downgrade it back to OS 3.1.3 or 3.1.2. As I understand the main problem is that I don't have SHSH saved for 3.1.3 or 3.1.2 anywhere. Is there any workaround of this issue or isn't it possible at all and am I stucked with OS 4 forever?