I'm a complete noob at this BUT.... I bought a secondhand iphone 3g last week which came with OS4 installed. I managed to jailbreak it using 'redsnow' but it lags sooooooooooo much and i was hoping to be able to downgrade to either 3.1.2 or 3.1.3. Are you able to downgrade an 8gb 3g iphone (model: MB489B) WITHOUT SHSH blobs??