Apart from the default modules that come with Perl, just DBI and the appropriate DBD module. All other modules should be optional.

There are no known issues with MySQL 5.

Things to check for your add.cgi:
- correct admin paths in use lib and init()
- correct permissions (user [if your server requires it] and execute permissions)
- for *nix system, is the add.cgi using dos line feeds?
- is the path to perl at the top of the file correct?

Adrian