Submitting a bug on this wont result in a fix - the problem is exceedingly unlikely to be on the phone itself.

There is no rule of thumb measure for replacing sim cards. They last for many years. (decades) Possibly when 4G services start appearing there might be a need, but that's a year or three away yet - aside from this, you'll need a new device to support those features anyway. 3G has been around for several years already, as have SIM cards that support it all.

You will not get a better signal if you swap your SIM card. Ever. The SIM simply stores an identity that the carrier uses to bill you (along with encryption info, address book, and a couple of other odds and ends - none of which are related to signal quality)

The problem you describe is the RF gap - this is handled by the RF Modem and Baseband in the phone - but equally as important is the picture the cell tower has about you as well.

To simplify things quite a bit - the post mentions they are interacting with the system at very minimal signal levels. The tower will periodically poll the phone, if it gets no answer it'll ask around but eventually conclude you're out of coverage area. Phone becomes an expensive clock. Switching modes on the phone will simply re-establish your phone as being active on the network, it might or might not be able to do this on its own - as was mentioned, it could take several minutes for things to come good on their own, or just not at all.

Issues at either end could see your cell phone lose signal for several minutes or more at a time. GSM is an extremely complicated system, to understand it to the degree needed to resolve the problem would require a few months of in depth study.

Short answer: Harass your service provider. They may be oversubscribing the cell system you are connecting to, might be that coverage is just crappy in your area and you need another tower installed to improve signal quality at your location.

Don't misunderstand me good sir, I'm not flaming you or criticizing, just that changing sim unfortunately will not resolve the issue.