update failed: 'RRset exists (value dependent)' prerequi

[sander815]

i have a problem with one of my domains:
i keep getting these errors in my /var/log/messages:

May 27 07:38:54 server01 named[6040]: client 80.61.222.21#43989: update 'ackerschott.nl/IN' denied
May 27 07:38:54 server01 named[6040]: client 80.61.222.21#43993: update 'ackerschott.nl/IN' denied
May 27 07:44:01 server01 named[6040]: client 80.61.222.21#44003: updating zone 'ackerschott.nl/IN': update failed: 'RRset exists (value dependent)' prerequi$
May 27 07:44:01 server01 named[6040]: client 80.61.222.21#44006: update 'ackerschott.nl/IN' denied
May 27 07:44:06 server01 named[6040]: client 80.61.222.21#44011: update 'ackerschott.nl/IN' denied
May 27 07:44:11 server01 named[6040]: client 80.61.222.21#44015: update 'ackerschott.nl/IN' denied
May 27 07:48:51 server01 named[6040]: client 80.61.222.21#44019: update 'ackerschott.nl/IN' denied
May 27 08:04:08 server01 named[6040]: client 80.61.222.21#44029: update 'ackerschott.nl/IN' denied
May 27 08:04:46 server01 named[6040]: client 80.61.222.21#44033: update 'ackerschott.nl/IN' denied
May 27 08:08:43 server01 named[6040]: client 80.61.222.21#44037: update 'ackerschott.nl/IN' denied
May 27 08:13:17 server01 named[6040]: client 80.61.222.21#44041: update 'ackerschott.nl/IN' denied
May 27 08:13:23 server01 named[6040]: client 80.61.222.21#44045: update 'ackerschott.nl/IN' denied
May 27 08:18:41 server01 named[6040]: client 80.61.222.21#44050: update 'ackerschott.nl/IN' denied


after reloading named:

May 26 20:31:59 server01 named[4564]: zone ackerschott.nl/IN: sending notifies (serial 2004052613)
May 26 20:33:24 server01 named[4564]: client 80.61.222.21#42891: update 'ackerschott.nl/IN' denied
May 26 20:33:36 server01 named[4564]: client 80.61.222.21#42895: update 'ackerschott.nl/IN' denied


i have no idea whats wrong with this domain
evverything is the same as the other domains on the server


$TTL 14400
@ IN SOA ns1.eska-hosting.nl. root.ackerschott.nl. (
2004052613
7200
3600
1209600
86400 )

ackerschott.nl. 14400 IN NS ns1.eska-hosting.nl.
ackerschott.nl. 14400 IN NS ns2.eska-hosting.nl.

ackerschott.nl. 14400 IN A 81.23.250.97
ftp 14400 IN A 81.23.250.97
localhost 14400 IN A 81.23.250.97
mail 14400 IN A 81.23.250.97
pop 14400 IN A 81.23.250.97
www 14400 IN A 81.23.250.97

ackerschott.nl. 14400 IN MX 10 mail


nameservercheck at sidn.nl gives me no errors

domain works normally though, as far as i can see

[sander815]

i thnik i found the problem

seems like the ip belongs to the clients itself, and i suspect hes having his internal win network named ackerschott.nl