Upgrading Drupal

If i have drupal 5 for example, and drupal 6 comes out. Do i have to start the entire site from scratch or can i use the modules that are already installed and just add new stuff?

Having a problem with multiple sites. When I duplicate one of my databases I get the following errors:

    * user warning: Table 'cache_filter' already exists query: CREATE TABLE geddon_buildagod.cache_filter ( cid varchar(255) NOT NULL default '', data longblob, expire int NOT NULL default '0', created int NOT NULL default '0', headers text, PRIMARY KEY (cid), INDEX expire (expire) ) /*!40100 DEFAULT CHARACTER SET UTF8 */ in /home/geddon/public_html/includes/database.mysql.inc on line 172.
    * user warning: Table 'cache_menu' already exists query: CREATE TABLE geddon_buildagod.cache_menu ( cid varchar(255) NOT NULL default '', data longblob, expire int NOT NULL default '0', created int NOT NULL default '0', headers text, PRIMARY KEY (cid), INDEX expire (expire) ) /*!40100 DEFAULT CHARACTER SET UTF8 */ in /home/geddon/public_html/includes/database.mysql.inc on line 172.
    * user warning: Table 'cache_page' already exists query: CREATE TABLE geddon_buildagod.cache_page ( cid varchar(255) BINARY NOT NULL default '', data longblob, expire int NOT NULL default '0', created int NOT NULL default '0', headers text, PRIMARY KEY (cid), INDEX expire (expire) ) /*!40100 DEFAULT CHARACTER SET UTF8 */ in /home/geddon/public_html/includes/database.mysql.inc on line 172.

Hello guys, same problem as http://drupal.org/node/115451

I have duplicate menu entries: Menu, Menu, blog, blog, etc. I have Internationalization mod upgraded too.

After I upgraded to 5.1 in most themes the horizontal menus bars (such as primary links and tabbed menu choices) is now a bulleted list. The most current themes such as Garland don't seem to do this. Any ideas on this?

New to Drupal. Set up 5.1 and liked it but noticed that several key 3rd-party modules are not available for 5.1 (yet, at least). Since I have almost nothing in the DB yet, I want to DOWNgrade to 4.7 for now. My question is this:

5.1 came with a script that did most of the dirty work of installation for me. Is there anything like that for 4.7?

Thanks for any help!

I've downloaded this patch:

http://drupal.org/files/sa-2007-005/SA-2007-005-4.7.5.patch

But it doesn't give instruction on where to put the code.

Anyone know?

Thanks,

Shai