I've been running into a problem over the last year pretty frequently.
When updating DNS NS, with relatively low TTL records, shaw always seems to be the last to update. Many update before the full TTL tick, and some are a little slower, but shaw often takes days!
Is this a known issue or am I just completely out to lunch.
My home shaw connection using default DNS still hasnt updated coming up to 24 hours, and im forced to use google or open DNS.