How did you try to downgrade? what steps did you do?
I went and downloaded the the firmware for the device that I wanted to downgrade to. Downloaded redsn0w mac 0.9.8b4. I also downloaded the latest version of Tiny Umbrella and made sure that my itunes was current.
On my mac I went in and changed the host files to point to Cydia's servers.
I backed up my phone, the proceeded to put it in DFU mode.
Started Tiny Umbrella and clicked "save shsh" and then clicked "start tss server"
I open itunes and it automatically detects that my device is in recovery mode. I hit restore while clicking the option key.
The device looks like it is going to restore but itunes always gives me an error message.
Tiny Umbrella is saying that I only have my 4.2.10 shsh saved. Cydia says I have my 4.2.9 and 4.2.10 saved.