Problem with catalog and modules changing URL and updating

[nalpha]

Hi, I would like to know how to fix this situation, thank you very much if you can help me with it.

I had a test installation some years ago with its products catalog and then moved it to another URL one year ago. I followed all the steps, change Url in the database ps_config but the website went blank. After some headaches I ran the website in the new URL but the site still was blank, and when accessing to the admin panel, I was able to see the products with its images but the modules page was absolutely empty. No modules at all. (Permissions were OK, and modules were uploaded).

This drove me mad. So I did upgrade and tried to import the catalog into the new website. But it did not work at all.

I'm thinking in a brand new installation. But I need help about moving the catalog products, images and descriptions.
Why this seems to be so painful?

Thanks a lot friends.