updating 3rd party code issue

Hi all,

I am trying to create a cvs repository for managing  modified openssl
distribution for my company. I am very new to CVS and ran into quite of
problems while doing it.. Please see the below listed steps that I followed
for doing it.

1)After setting up the repository I imported the openssl code that we are
using to the repository using:

cvs import -m "Import of openssl modified 0.9.8g" foo_openssl/openssl
OPENSSL_DIST OSSL_0_9_8g

Note: This distribution has few files which did not come with openssl
distribution. We added those files to the distribution and we also modified
quite a bit of code

Once the import is finished I did CVS commit

2)Now I want to upgrade this version with the new version 0.9.8m and merge
all our changes to that version. To do that I ran cvs import again:
cvs import -m "Import of openssl 0.9.8m" foo_openssl/openssl OPENSSL_DIST
OSSL_0_9_8m

This step was successful without any merge conflicts

3)Now to merge the changes between both tags I did
cvs checkout -jOSSL_0_9_8g -jOSSL_0_9_8m foo_openssl

Now when I look into the checked out source all the files we added are
gone/missing. Also, lot of the changes we had did not merge into the new
distribution. Also, it did not report any merge conflicts which was also
incorrect...

I am looking for suggestions on what is the best way for doing such a thing
with CVS...

Thanks,
Kunal