Whenever I leave a connection on for any period of time, it disconnects itself automatically. I don't have autodisconnect installed or anything like that. It there something in the settings that does thing? Or could it be an application interfering with the settings?

And internet connection icon has disapperard?This happend me when i was usin 2G connection,or if you have setup automaticly finding wifi connection(mayby that find connection and than when is siginal out it has disconnect)....

I don't have wifi scanning on. It might be that it disconnects when I change from 3G to 2G, but it didn't use to do this

If you are running on a cell connection and the signal wavers or the cell you're connected to is swamped then this sometimes happens. It seems to be that if the N900 doesn't get a response in a reasonable period of time it assumes the connection has stopped listening and gives up. I haven't been able to verify that is what happens but it does seem to fit my experience.

I can verify this to be problem. Sometimes when i drive to work (takes about 30min) and when im finally @work n900 has lost connection and my skype/msn/fb chat is not connected anymore. It did that even when i didnt have autodisconnect.

I don't think its necessarily that it disconnects, its the fact that it loses the connection and does not re-connect it. That is certainly a problem I have been having since I flashed to PR 1.1.1, it seems even with Connect Automatically turned on it usually does not if the connection drops.

I have been ignoring the problem figuring it will probably sort itself out when PR 1.2 comes out.

[EDIT]
I think it might be working again at the moment, go figure.

Yeah, same problem here. When I have a 3G connection for a while with msn online, it suddenly disconnects without warning. Very annoying because I was looking to have a msn connection always on.

Let's hope it gets fixed.

Did this get fixed? I am still having this problem and I have the latest updates.

I have this problem when tethering to my computer. The phone loses GPRS connection after some time. What I do is reboot the phone.
Here is a bug report that seems to be about this bug. If you have this bug, please vote so they'll fix it.
https://bugs.maemo.org/show_bug.cgi?id=7932

I changed my APN from internet2.voicestream.com to epc.tmobile.com. I can tether and keep the connection without a problem now. Will update if problem reappears.