named shows different results

[fedora]

Hi listers

I have a very curious problem here:

I changed some CNAME entries in the named for a specific domain this 
morning.

when i now (from an internal workstation) do a
dig @nameserver cname

i get a different answer, depending on whether @nameserver points to the 
local address 192.168.... or on the public ip address 212.90..... of the 
nameserver

in the first case, named returns the old (incorrect) address of cname.
in the second case, named returns the new (correct) address of cname.

when i let @nameserver point to the secondary nameserver, the above 
difference does not show up, it always returns the correct address.

from the outside world, the new (correct) value is always returned.

what could the problem be and how to avoid it?

thanks in advance

suomi