This is a known problem with 2.0.7 glibc. I've just spent 4 or 5 hours tracking it down, and I much would have rather found out about it somewhere in the man pages, or any other documenatation. Please help to try to get this fixed.
The main problem here is that if you use NIS with a netgroup, putting the netgroup name into hosts.lpd doesn't enable remote printing. It makes it more difficult to manage a print server.
is this bug stilol valid with RH 6.0 ? On RH 5.2, was the nss_Compat module used (the one that supports netgroups)?
One must use the nss_compat module to have netgroups support. Bug closed because of lack of feedback