I have an N900 with PR1.2 (uk) and the usual stack of apps.

I'm finding that on occasion the phone stays disconnected from 2g/3g even when returning to an area with signal. I've not found a particular pattern except that it almost seems as if it "gives up".

A colleague has similar behaviour (same operator/device/location)

I'm on the "3" network in the UK. Despite relatively decent coverage in the general area I lose cover
- at home (except in some upstairs room)
- at work (large site - some areas work, office is just about ok at desk, walking around will loose it)

An additional complexity is that in the uk 3 operate only a 3G network. They have an agreement with another operator for 2/2.5/2.75 cover (orange) and the phone will ROAM onto this network quite happily. I believe they even have in-call handover sorted and think all handsets are in the roaming partners HLR

Any thoughts on what may cause this. I think the network/roaming may be a contributory factor. I think I only ever see it when in a dodgy coverage area but surely ultimately the phone itself should be retrying - even only occasionally.

Does anyone else seem similar behaviour

Wifi is unaffected as is general operation of the handset
On a related topic, any good pointers on the GSM modules on the N900 - especially api/dbus messages etc? source code? (assume it's proprietary) -- wondering if it might be possible to "prod" the module every say 20 mins just as a fallback.

Please vote for the bug in my signature.

I've noticed this too. I usually just switch to offline mode and then switch back to normal mode.

The H3G network is a real mess. They have a fair 3g coverage map but the problem is that every voice call or data unit that occurs on the 'borrowed' 2g network costs 3. They get no money and its costs them. Think about that for a sec.
Hence H3G mandates that the phone tries desperately to get to the 3g network. This can have quite nasty side effects as you are finding. 2G searches are delayed due to extended 3G searches.
Its news to me that H3G use orange as the 2G fallback - IMHO orange is a pretty piss poor network on the 2g side - no nice 900 MHz allocation, just the crappy 1800.

The source for the celluar side is closed. Full stop.

Given the widespread reports from people here, I am convinced that it is not a network issue. I am on Tmobile USA and experience this issue almost daily. I am in the process of trying to capture what the device is doing now in a syslog so I can post it to bugzilla.

I regularly get my phone to fail connecting. If I manually try to connect to a network it says it can't and ask if I want to try again.

Switching to offline mode and back seems to always solve the problem.

Well, just as I thought. The minute I try to recreate the bug I can't

To anyone else with this issue - Please create a syslog and try to recreate the issue. Instructions are here:

http://wiki.maemo.org/Documentation/.../maemo5/syslog

Then post the results to the bug in my signature so Andre can try to figure out the root cause. Make sure you DO NOT leave syslog running (sudo gainroot; stop sysklogd after creating the log) as it can fill up your rootfs.

Wow. didn't realise it was so widespread. I was going to enable syslg anyway so will check the instructions tomorrow. Glad to see there's a bug open and happy to try to capture more data, though Im not at wok (where the problem happens most) tomorrow.

None of the networks are perfect, and 1800/2100 have less penetration than 900, but note that 3 also have more xmitters - and with the passing off of the 3+tmobile 3G network to MBNL, *and* now the orange/tmobile merger there could be one uber network in the UK

From what I've seen 3 also tend to have good backhaul/speeds rather than O2 (especially) and vodafone (such as lack of edge in most places)

So pure coverage - voda I'm sure, good fast coverage - 3... and yes I'm very very torn.

i never had this problem.
Vodafone NZ using 1800/2100 and I never get that problem.