Upgrading Drupal

Upgraded from Drupal 5 to 6. Using Image module.

Created view, block, with link to image gallery (..../image). Works fine for admin -- the link leads to the Image Gallery page, which displays a table with the various image galleries. Also, when I click on any image, I get the breadcrumb home>image galleries>[gallery name] The breadcrumb links work fine. All is well.

But when I log out, the image galleries page (..../image) displays "there are no images in this galley" and shows no content.

I have an up-to-date multisite installation of Drupal running many sites just fine. However, the busiest of them is significantly slower than the rest and I have noticed that it takes a long time for any admin task, or even longer than normal when adding a node or editing. I have noticed that the watchdog table is empty and nothing is being written there as well.

I suspect a failed upgrade at some point. This site in particular was created back in v4.6 and I have being upgrading/migrating since. It might just as well carry plenty of useless variable info, etc.

I upgraded from 6.13 to 6.14 and a strange thing happened...

On the home page there are the list of articles with teasers etc. Normally you click on the title of the article and you are taken to the article's page. This doesn't happen anymore - a check in firebug shows that the href attribute is empty in the <a> tags...
It may be something I have done - I have only recently started experimenting with drupal.
Interestingly, this does not happen with certain blocks.
It happens with normal presentation, views and panels.

What to do ?

For the purpose of this post "mySQL" is the database type I refer too, though this problem does effect users of other types as well.

I am wondering if anyone here knows of some good software for merging changes that have taken place in a development environment and the production site, so that if minor and or major changes are made to the test site, while data only in general is entered into the production site, that the two seamlessly become one without loosing anything.

It is also quite important that any such software is usable by those with limited database/shell/development experience.

This issue appears to be a problem for many uses of Drupal and other CMS systems alike.

I have found DataSync at http://www.spectralcore.com/syncdatabase/ and other options as shown here http://www.spectralcore.com/order.php?product plus other options like K DataBase Magic found at http://www.databasemagic.net

The software options above appears to be what I need but I don't want to buy something that is not really suitable. I simply do not understand enough about this to know for sure, without asking for the help of others who have much more experience than I do with this sort of thing.

I thought the upgrading process from 6.10 to 6.14 went well until I got an error message while updating the database.

Message:
An HTTP error 501 occurred. http://localhost/drupal/update.php?id=3&op=do

What could be the cause of this problem?

Your kind help will be greatly appreciate.

Is it true that the "dbscripts" package located at http://drupal.org/project/dbscripts is the best way to manage database merging??

I read on Kathleen Murtagh's site (the developer) located at http://ceardach.com/blog/2008/06/development-production-database-merge-s... that apparently there is no other way to do this other than repeating your test procedures within your production site.