6.2 megabits per second download, .55 upload in Chicago. Worked in KC just fine. I am starting to think that the network upgrade was the cause of the connection errors.

I was just in Atlanta for a couple of days and got outstanding signal strength and a regular 3.5g connection. Now I'm back in New York and it's back to the same flakey connection, so yeah...I'd say it's T-Mob playing around with their network, I hope they sort out my area soon!

Wow, I have been living with this same exact crap for months and I always thought it was just my phone. I seem to get a few good weeks then it's back, plus mine will sometimes show no signal (2G or 3G) for up to a few hours. I notice if I try to go into 'Phone' under 'Settings' when it's doing this it hangs and doesn't want to read the SIM. I'm losing track of how many times I've flashed my N900.

Took my phone to my local t-mobile store last week and got my SIM swapped with no difference. Interesting part was that they put it in an HD2 it did the same thing! Submitted a trouble ticket to t-mobile engineering and over the weekend received an "issue has been resolved" message.

At the moment I cannot get continuous throughput on 3G even though it shows full bars, it just stops downloading. Also, if I change the APN and try to reconnect to the internet it will often fail initially. Phone calls over 3G appear to be working for now.

Questions for others with the same problem:
-Have you tried your SIM in another phone and if so what did it do?
-For those who have sent their phone back to Nokia, is it working now? Perhaps they did more than just the standard reflash?

Thanks for reading and good luck.

Hey Guys - I am down under in Australia on the Vodafone Network and have had the N900 for about 5 months now..... No support from Nokia here...

I have had my sim car replaced from Vodafone a couple of times now.

Am having the same issues - Network Error, Call not Established, General Error etc when I try and make a call. A simple reboot fixes the issue, but is really annoying when you need to make a call.. Lol...

Sometimes if I make a call out then I will receive a bunch of sms that were sent hours ago and I only receive them if I make a call out.

So I don't think it would be a network issue, if I am in a different country with a different provider - Correct me if I am wrong, but I think it maybe the phone

I am currently in St. Lucia and bought my N900 last year in December and it has been working fine since up until a two weeks ago. I am now having the same connection issues as most people in this thread and after some troubleshooting here are my findings:

1. It's not a problem with the network. All the phones in my house don't seem to have problems connecting to the cellular network. Most of them have full signal strength and my N900 doesn't even show the bar.

2. I get signal strength only when i leave my house and i used to get full signal strength at my house before. I don't understand it.

3. Tried securing simcard at the back and that didn't work either.

3. Deleted all applications, cleaned out device and reset to factory settings and still it doesn't work.

4. I can't re-flash the device as my micro-usb port popped out a couple of months ago. I can't send it to nokia either as i Overclocked the phone and spoilt my warrenty.

5. Toggling the offline mode doesn't work either. I don't know what to do....please HELP!!!!!

Still (11/11/2010) same problems on Chicago T-Mobile network (after having read the many comments here, with common thread being T-Mobile, I definitely exclude this as being a Nokia N900 problem). Three questions for those more up to date than I:

1. Is a SIM card swap confirmed as possibly restoring the service?

2. Could someone confirm that a new(er) SIM card has a set of numbers in the upper right corner (aside from those running "horizontally", as described to me by a T-Mobile rep, when troubleshooting other issues a few weeks ago)? Is it true that's indicative of 4G support in the card?

3. Is Nokia N900 capable of using 4G on T-Mobile USA?

I just encountered this on AT&T network. Got kicked off a conference call, now can't make any calls. Great.

EDIT: put sim in E71x, and can now make calls. Looks like an N900 issue for me...

all those who are facing "general error" and can't make a call please change your settings "send my caller ID" to let network choose from---
--settings> phone> set my caller ID to "let network choose"