can you update/restore a jailbroken iphone 3gs without losing jb?

[threetimesdaily]

i have an iphone 3gs that i jailbroke on 4.0 software. my itunes is still running 4.0. all my media synced but when i tried to put ringtones (.m4r) on my phone it says:

"iphone" is synced to a different itunes account you must erase contents of iphone and restore with contents of this itunes account.

which would be fine because its all my media and it wasn't synced to a different account, but it automatically updates to 4.0.2.

is there a way to restore my iphone without updating and continue to use my jailbreak? if i update do i have to jailbreak it again?

 

[Myzhi]

Syncing doesn't auto update your firmware. I sync with with IP 4.0, 3GS 3.0 and 2G 3.0 in ITunes just fine. And, no, if you upgrade or restore your firmware, you will loose your JB.

 

[threetimesdaily]

i unlocked it with redsn0w, will restoring it affect sim capabilities?

 

[Myzhi]

Yes. Restoring the phone with the official firmware will remove your JB and unlock.