DNS resolution problems on the router

Hi

DNS resolution works fine on clients connected to my router however when I do an nslookup on the router itself it occasionally fails to return anything and it always returns an error.

Eg

root@openwrt:~# nslookup czech.privacy.network
Server:		127.0.0.1
Address:	127.0.0.1#53

Name:      czech.privacy.network
Address 1: 143.244.59.131
Address 2: 143.244.59.141
Address 3: 143.244.59.152
Address 4: 143.244.59.172
Address 5: 143.244.59.161
*** Can't find czech.privacy.network: No answer

If a dns lookup fails on the router then doing on the a pc on the lan will work, subsiquently so will the lookup on the router.

Notes.

I'm using davec502's latest build for my linksys router.

I have an openvpn connection running most of the time. There is a script which switches dnsmasq from the dns servers defined in the WAN interface config to the DNS hosted by the VPN provider. The same issue occurs regardless of whether the vpn is up or not, ie regardless of the upstream dns.

Any thoughts where to go looking to diagnose this issue.