Upgrading Drupal

Hi all, currently I have a few sites all with their own drupal installation, but installed on one server and i would like to change it into a single multisite installation and need some advice. I wasn't sure which category to put this post in as its a post-install upgrade re-install conversion or something... but anyways...

My setup is:
/public_html - this has my main site with drupal 5
/public_html/sub1 - this is a subdomain running its own installation of drupal 5 which is accessible via sub1.mymainsite.com
/public_html/sub2 - same as above
/public_html/sub3 - same as above
/public_html/addon1 - this is an addon domain and is accessible directly via www.addon1.com (i have a hosting account which allows multiple domains per account)
/public_html/addon2 - same as above
more addons and subdomains will be added in the near future I guess

to make matters slightly more complicated all domains are drupal 5 but different versions, and one site is drupal 4.7.

Firstly, I'm guessing I should upgrade all installations to the same version? (I wanted to avoid this step as the whole reason I want a multi-site is cos I'm fed up of maintaining each installation separately! but I'll do it one last time if need be)

I am running Drupal 5.5 as shown in the CHANGELOG.TXT, but the Update Status module (5.x-2.0) is seeing core as ver. 5.3. I haven't been able to figure out why. Any suggestions on how to correct this, so the installed version appears correctly, would be appreciated.

Screen caps are on my site at http://tomrue.net/?q=version_inconsistency.

Thanks, and Happy New Year.

Tom

I gave the ads module full access for everyone in "show advertisements". But the ads only showed in admin login. It didn't show up in others, such as "anonymous user", "authenticated user"

I have a site I've built for a friend and they emailed me wondering what's wrong with the site. It's www.appliedfaith.com and it's simply not showing up. Looks like the css is broken or something. Anyone have any clues? This site has been up and functional for a year + and all of the sudden it's having issues.

Thanks for any assistance with this.

I tried to upgrage from 6b4 to 6rc1
the update.php gave me the following message:

"An HTTP error 406 occurred. http://yossin.com/testd/update.php?id=2&op=do"
(the "id=2" is because I have run update.php twice)

after that, the status report tells me "Some modules have database schema updates to install. You should run the database update script immediately"

I'm running drupal 4.7.2 and am thinking of upgrading to 5.X I need to know though will an upgrade effect the user database tables? I'm also running a script called amember(http://amember.com) that works with the database to create subscriptions for different user levels. If an upgrade will effect the user database then I don't think I can upgrade, but feel like I should as it has been over a year. Does anyone know if an upgrade to 5 would cause problems for me? Thanks.