Should ios 4.0 keep wifi alive while the screen is locked?

[weaksos1]

On my black iphone 3G on ios 4.0 I think it kept wifi alive... I only had the phone for a week, at most, but I recall getting an instant message through wifi (I don't have a data plan) once or twice while the phone was locked for hours (e.g. when I was sleeping). My current white iphone 3G on ios 4.0 for sure doesn't keep wifi alive. I have insomnia installed but if I leave that on it burns through my battery-- like 4% an hour (compared to the close to nothing per hour it uses with wifi off). I don't recall the black iphone burning through battery while locked.

Anyways, my question is should ios 4.0 be keeping wifi alive on my phone while the screen is locked?

[babalao20]

Yes, if your phone is always in the wifi range. Unless you off the wifi via the settings or you completely off the phone.

[weaksos1]

Yes, if your phone is always in the wifi range. Unless you off the wifi via the settings or you completely off the phone.

Thanks for the reply. Why do you suppose wifi is not staying alive on my phone when I lock the screen (it is within range when it drops wifi -- about 30 seconds after locking the screen, and then it picks it back up within a few seconds of turning the screen back on)? Should I try to re-download the IPSW file and shift+restore it?

Also, if I restore it, is there a way to back up everything on my phone up (including official and unofficial apps) so I don't have to re-download and re-install everything?