Should I upgrade to 4.1

[eyaln]

I have a iPhone 4. It was jailbroken using jailbreakme.com and has not been unlocked, although I would like to retain the ability to unlock.

I'm running version 4.0.1 (8A306) and my modem firmware if 01.59.00

My question is, can I upgrade to version 4.1 and if so how? Also, is there any risk to this update, like not being able to unlock anymore?

Last question, I don't fully understand the modem firmware, but assume I want to keep 01.59.00. How do I know if what I'm doing is changing modem firmware.

Thanks in advance!

[iYeow]

You can preserve your baseband but need abit of work to get to that. If you don't really need an unlock in the meantime, just upgrade to 4.1.
An unlock will come sooner or later, it is just a matter of time before they figure out the unlock.
An unlock is necessary only for those who need it immediately as they are not with Official carrier.
If you do decide to upgrade to 4.1, you can either use GreenPoison or LimeRa1n to jailbreak.

[eyaln]

Is there a tutorial for preserving baseband?

[iYeow]

Not sure about tutorial on the website, you can google search.
My tutorial if you want to know.