When attempting to synch my Iphone 3GS i was prompted to update the OS to 4.0.1. During the installation an error message appeared, unknown error 21 was given as the reason. After this the iphone has apparently entered 'recovery mode' and needs to be restored before it can be used again. However when i try to restore it it gives the unknown error 21 and doesnt complete the task. I was initially using ITunes 9.2.1 and have tried to restore on a different computer with another version of itunes but get the same error message. Looking up error 21 apple seems to suggest this is an error that occurs with anti virus software interfering but i am not running any anti virus software that i am aware of. Can anyone help or have i bricked my iphone?