NIS Group Lookup Problem

I'm running a NIS on an network of Ubuntu 8.04 linux systems. I'm seeing a weird problem where the 'id' command is not returning all the groups I am a member of. For example:

alex@client $ id -Gn
localgroupA localgroupB nisgroup1 nisgroup2 nisgroup4

alex@client $ id -Gn alex
nisgroup1 nisgroup2 nisgroup3 nisgroup4 nisgroup5 nisgroup6 localgroupA localgroupB

So the symptoms are, specifiying the user in the 'id' command puts all the local groups at the end of the lookup instead of the beginning, and shows all the actual NIS groups that I'm a member of.

Has anyone seen this before? If there's any more info you need, please let me know.

My /etc/nsswitch.conf file is specifiying "group: nis files" for lookups.