troopie wrote:I have to report that I have had more than one bad experience with Thai Military Bank ATMs. They have almost never allowed me access to my old Citibank bank account in Japan, so maybe they should be on the black list!

It is nothing to do with the banks directly. They make money from issuing cash for a small feee and taking their share of exchange rates.
The world's banking system (I am sure that I have written this before) is connected together by networks operated ny large FIs (financial institutions).
These are notably Vis, Amex, Master Card (Maestro) and JCB.
The usually use privately owned networks. Every transaction goes through many different computer nodes before the ATM allows you to draw cash.
You can not blame the dispensing bank for the failure. It could be one of a thousand reasons.
What I do blame the banks for is there economy of messaging. "Please refer to you bank" may actually mean that the bridge from Thailand to Singapore is at full capacity and your bank knows FA about your request.
The reasxon that you are more likely to get a failure here when drawing from a Western Bank is twofold:
1. There are many more nodes that have to process the transaction.
2. The local infrastrucure is not maintained to the standards that you are familiar with in the West.
It is good advice to check that the badge on your card is supported by the machine you are using. In the event of failure then use a different bank after 30 minutes or so. If no banks get through then the problem is probably with local infrastructure.