I am popping up a new server, replacing an old one with MySQL 4 with a new one, and I put MySQL 5.1 on it. (The 5.1 is NOT yet online, the 4 is still live).

So my old webpage servers have the MySQL 4 client. I tried to concurrently install the MySQL 5.1 client, but it won't let me- I have to uninstall the MySQL 4 client first. So, should I do this (will the 5.1 client be backward compatible with the current 4 database?) or so I wait until I get the new server installed, close all the sites, remove the 4 client, install the 5.1 client and bring them back up?

Does that make sense? Can I use the 5.1 client on the 4 database is my question. Can I "pre-install" the client upgrade, or do I do it when I do the server changeover?

Thanks!