I'm trying to change my nameservers on my domain to ns1.domain.com and ns2.domain.com, and put in the correct IP's (xx.xxx.233.166 and xx.xxx.233.167) - obviously blanked out there - and I get this response:

Please wait...
Failed to change nameservers for alexblundell.com
Unable to modify nameserver Invalid Parameter: IPv4 '' is invalid
Anyone else had this issue?