Problem upgrading glibc.

[warder@pcisys.net]

Hi,

I have RedHat 5.1 and was trying ti upgrade from glibc-2.0.7-13 to
glibc-2.1.2-2 and it seriously scrwed up my machine. I couldn't log
in, and most of my programs wouldn't run.  The errors I got were:

error in loading shared libraries: /usr/lib/libdl.so.2:undefined
symbol: dl_default_scope

After renaming /usr/lib/libdl.so.2 to try and work around the problem
I got:

error in loading shared libraries: /lib/libnss_nisplus.so.2: symbol
nis_local_directory, version GLIBC_2.1 not defined in file libnsl.so.1
with link time reference.

After renaming that:

error in loading shared libraries: /lib/libnss_nis.so.2: symbol
yp_get_default_domain, version GLIBC_2.0 not defined in file libnsl.so.1
with link time reference (no version number)

After renaming that I was able to log in properly ( I had been breaking
out of the boot process and manually mounting my partitions) and
rpm -Uvh --oldpackage back to older versions.  The only one that 
didn't give the same (or very similar) problems was my original
glibc-2.0.7-13 (even 2.0.7-30 didn't work)

Can anyone tell me what my problem is and how to successfully upgrade
my glibc?

Thank you in advance.
                                        -Govind Salinas