In following the directions for install of guestAdditions
yum install of gcc seams to hang in centOS under VirtualBox

What exactly happens when it 'hangs'? what's the last output of your command? What exactly is your command?

and HOW!!! are you installing gcc?
the correct way is

I always get the same repeated message in yum.log when it tries to update glibc-common

Also whether you run yum install gcc or the install syntax you suggested, it always hangs in the
same place, i.e when updating glibc-common: Here is the repeated message verbatim form yum.log:

Gconf Error: Failed to contact configuration server; some possible causes are that you need
to enable TCP/IP networking for ORBit, or you have stale NFS locks due to a system crash. See
http://projects.gnome.org/gconf/ for information. (Details - 1: Failed to get connection to session:
Did not receive a reply. Possible causes include: the remote application did not send a reply, the
message bus security blocked the reply, the reply timeout expired, or the network connection was broken.)

Note: I've been googling for 3 days on this error message and have gotten no answers that solve the
problem. I downloaded the iso from SentOS. It automatically logs me in with the full GUI as
centoslive@livecd. By the way I havn't figured out how to login as root because it automatically logs me in with
(I guess) the username:livecd.

I'm wondering that this may be a problem and the configuration server doesn't know how to parse the machine
name@username properly.

So there it is.

I always get the same repeated message in yum.log when it tries to update glibc-common

Also whether you run yum install gcc or the install syntax you suggested, it always hangs in the
same place, i.e when updating glibc-common: Here is the repeated message verbatim form yum.log:

Gconf Error: Failed to contact configuration server; some possible causes are that you need
to enable TCP/IP networking for ORBit, or you have stale NFS locks due to a system crash. See
http://projects.gnome.org/gconf/ for information. (Details - 1: Failed to get connection to session:
Did not receive a reply. Possible causes include: the remote application did not send a reply, the
message bus security blocked the reply, the reply timeout expired, or the network connection was broken.)

Note: I've been googling for 3 days on this error message and have gotten no answers that solve the
problem. I downloaded the iso from SentOS. It automatically logs me in with the full GUI as
centoslive@livecd. By the way I havn't figured out how to login as root because it automatically logs me in with
(I guess) the username:livecd.

I'm wondering that this may be a problem and the configuration server doesn't know how to parse the machine
name@username properly.

So there it is.

P.S. I posted the same reply to Guru.

well
AGAIN , how are you trying to install gcc ????

if you are trying to do this
-- IT WILL NOT WORK ---
"yum install gcc"
will NOT work well

That will NOT install ALL THE OTHER software that is NEEDED by gcc

install the development group


also
that is telling you you have no internet access

what is the output of this
it should be something like this

if you read my post, I installed the development group and had the same problem as yum install gcc
because both hung has per my post for the same reason.

can you ping google ?