I'm also having the same issue.

iPhone 4 on iOS 5.0, Maxis set, non-jailbreak.
Starting 2 days ago, the signal became weird. My house area signal is quite bad, but the problem is once the signal lost, it will never be able to connect back (forever Searching... or No Service). The only solution is restart the device.

I just restored my iPhone. The problem seems gone for now. Hope it won't come back again

No my 3G and Cellular data is both OFF all the time (my free data plan is over)
And I did mention my problem is:

Before this, when the network is lost, it will automatic find back the network and connect back, or I can manually search for network to connect
And now, once the network is lost, no matter how long I search for network, there will be no result (even I'm in good coverage area), and the screen only shows searching... And no matter what I do (turn on/off airplane or whatsoever), I'll NOT be able to connect back unless I restart iPhone.

This post has been edited by huiqing88: Nov 10 2011, 02:34 PM

When I fresh upgrade to iOS5.0, also no problem at all.
And I'm not the only one with this situation. Look at most people replying in this post.
I guess this might be one of the unknown bug in iOS5.0.

The way I know that solve this problem temporarily is to restart/reset the device... It worked on my iPhone...
But it seems doesn't work on yours... Maybe your case is even worse...

If you manage to get the network back, then it just simply temporary network loss problem, not the one mentioned in this thread.
Your case should be fine and normal.
The case in this thread is that once you lost the signal, you never able to get back the network.

Boo... After 5 days of iOS 5.0 restore, the problem just came back just now

This problem make iOS 5.0 the worst iOS I ever used

I don't mind blue tint; I don't mind antennagate; I don't mind easily spoiled home button; but I can't accept that a phone can't be used as phone
iOS 5 really disappointed me.
And, I can't restore to iOS5.0 now. Thanks to Apple.

This post has been edited by huiqing88: Nov 14 2011, 07:56 PM

I can tell you the result is the same. It's a software problem.
You can check on this thread https://discussions.apple.com/thread/345173...tart=0&tstart=0
All the people there are facing the same problem, and no matter what they did, the problem persist.
And most of them are 4S users. I'm not sure about 3Gs though.

This post has been edited by huiqing88: Nov 14 2011, 08:12 PM

Antennagate was actually not a serious problem, just that the media exaggerate it as a HUGE flaw in iPhone 4.
I can live with that, since I will certainly use a case for my iPhone 4.

However this time, the network problem is not only on the 4S, it's on the iOS 5 itself.
And yet Apple still does not respond to it until now.

Trust me, the no service problem will come back anytime later.
At least not immediately after you restore.
iOS5.0.1 doesn't fix the said problem.

My friend and I both on iPhone 4 and upgrade iOS5 at the same time; we both have iMessage activated.
My iPhone suffered from this problem twice already (1 restore in between)
However, my friend's iPhone still working fine until today.

This problem really happens too random.
Need more observation and investigation.
Since you suspect its iMessage causing problem, have you tried turn it off and see if problem persists?

Come on guys let flood Apple with our complains!
Although they might not even care

http://www.apple.com/feedback/iphone.html

I'm also hotlink users and I off cellular and 3G all the time (no more free data plan) and I'm also suffering this problem.
This happens randomly; it doesn't matter what carrier you're using.

Is your problem exactly the same as what we mentioned in this thread?

This problem not only happened in Malaysia, it happens everywhere.
For reference:
1. Signal bug in iOS 5
2. iPhone 4 after iOS 5 update keeps searching for network and stays with no service
3. iPhone 4S "no service" problem
4. iPhone 4 (iOS 5) stays searching network, i need help!

and much more...

Haha not to scare you but everything will be working fine after restore but it will eventually come back...
I'm one of the unlucky one

This post has been edited by huiqing88: Nov 17 2011, 06:01 PM

You didn't install semi-tethered?
So that your phone can still be used (with limited functionality) after restart...

It's not. Mine experienced this problem twice without jailbreak, both times on 5.0.
Now on 5.0.1 and jailbroken, this problem has not yet come back (finger crossed)

Not released yet.
I'm using semi-tethered jailbreak.

If you can re-discover the network, then your iPhone is fine...
Our mentioned problem is once the network lost, will never able to find any network...
Need to restart only able to find network (but the same problem will occur again)

After restored to 5.0.1 like 5 days without problem...
This problem had once again come back...!
DAMN!!!

Really super frustrating! Had to restore once a week?
Did Apple actually tested their iOS before launch?
First the battery issue (big issue), then now this no service issue
Don't tell me none of the testers did actually faced all these bugs
Really really really disappointed on this iOS 5!