ignored TTLs?

[aklist_bind at enigmedia.com]

>
>> I then changed the IP address for the corresponding A records (they
>> did not have their own TTLs separate from the main TTL), set the TTL
>> back to 3h,
>
> This is careless, should anything go wrong. It would have been better
> to wait a bit to see if everything was OK.

I did test it, and it appeared to be OK. The main issue for me is, the TTL 
is 3h and 48 hrs later some hardware is still caching the old IP address.

>> Question is, what did I do wrong?
>
> You apparently did not indicate the domain name so it is quite
> difficult to debug.

Sorry...the domain is my-gym.com

> Shot in the dark: the domain name is also known by
> the registry of the TLD, they publish glue and you did not tell your
> registrar to change that glue, and so the TLD name servers continue to
> "pollute" the DNS?

I guess I deserve to be flamed, but I don't completely understand the 
significance of what you're saying.

I did not change the authoritative NS for the domain, just the A record, and 
I thought the glue records referred to NS declaration in the domain file 
itself? In which case they're there?

Please help me understand where I'm going wrong here. I thought I had been 
following the correct protocol per my reading of DNS & BIND.

TIA, Andrew