A friend and I have had the same problem. I have a Nokia N95 and he had a different quad band.
When we check balance, we get "No network coverage". When making a call, we get "Connection Error". I manually linked the phone to the Digicel network and have a full set of signal bars.
I noticed the following when searching the internet, aparently there is an "odd frequency pairing" issue with the Jamaica and Thailand networks:
Quoting the article:
"Using a Treo 600 in Thailand or Jamaica
The GSM mobile network systems in beautiful Thailand and lovely Jamaica have a special trait: they use unusual bandwidth pairings. In most countries, GSM networks use one of two combinations of bands: either the 1900 and 850 MHz bands, or the 1800 and 900 MHz bands. Thailand uses the 900, 1800 and 1900 MHz bands concurrently. Jamaica pairs the 1900 and 900 MHz bands.
So?
This makes it more difficult for your smartphone to decide upon a band. Once your smartphone finds one of the frequencies, it makes an assumption about its location and stops searching for the other set of bands. For example, if it detects the 1900 MHz band, it will then begin searching for the 850 MHz band, because that's what most countries pair. It won't look for the 1800 or 900 MHz bands, even if your SIM is from a mobile service provider that uses the 1800 or 900 MHz band.
The result? Your Treo may not be able to attach to the mobile network, and Wireless Mode will not work.
What if it happens to me?
The easiest way to solve this issue is to install the Treo 600 Updater, which eliminates the need to manually select the band every time you turn off Wireless mode. Install the Treo 600 Updater, and you should not see this issue."
Herein lies the problem: If I go to [Search Bands] I can only select 900/1800 or 850/1900, which may not match the pairings available in Thailand or Jamaica. I'm assuming I got the latest Phone Updater when I installed FW 1.71 and SW 1.20-ENA. Should I search for a Treo 650 Phone Updater?
http://mytreo.net/forum/index.php/topic,34628.15.html
