I recently did a mass SMS send to a client's customers using Clickatell. The messages were sent with a friendly non-numeric caller id (eg NATE) rather than a phone number.
All recipients on Vodafone received the message with this correct caller ID.
Some recipients on Telecom received the correct caller ID, others received it from a +44 number (Clickatell must've routed this message through the UK).
Anyone know the reason for this? Is it a per phone thing, or is it the network? I'm really curious to see if it's not fixable from my end.