I use a Vodafone Australia SIM which has global roaming enabled so I can receive SMS from my bank. However the phone seems to have a lot of trouble connecting to a network (which turns out to be DTAC). I have to restart the phone many times before I have success, otherwise it just says 'Searching..' It has no trouble connecting to the network with a local SIM. I'm wondering if there is anything I can do in the settings to make connection a bit easier. The phone is Motorala V6, about 5 years old.

First thing to try is, try another phone and see if that fixes it.

can you manually select local network provider other than automatic selection? if manual try AIS also may have to review phone setting such as setting on auto lock to "never"

I pulled the SIM out and put it back in again. Now works flawlessly. Go figure...

I have had a vodafone sim in cambodia for years, only used for the occasional text from my bank when transferring money.A few months ago the phone would not receive texts from two australian banks, yet texts fromf friends came through.

Neither vodafone or the banks had an explanation.