Blank pages after uploading theme and database

Hello.

I have a multisite installation on a production server and one installation on a development server. Before I can export the database to the production server - I need to change the theme to garland and then change it back to the custom made theme. If I don't do this I get blank pages when checking it on the producation server.

I want to remove the tedious process to change the themes on and off. I do this several times a day. Any ideas to a solution, or similar experiences?

I think it might have to do with the paths to the themes that differ. I have changed the setting for the path in /admin/settings/file-system so that both have the correct production domain. On the development server I have symlinked production domain to the local development domain, like "ln -s site.local site.com".

It can have something to do with the domains and Drupals caching mechanism. I suspect Drupal somehow caches the URL requested by the browser. (First I use "site.local" on the development server and then export the database to production server and use "site.com".)

The custom made themes are made with the Zen theme.

The export of database I do like: "mysql -h producation-server.com -u username -ppassword databasename < site.sql"

The theme is uploaded manually via FTP.

Thank you for your time.

Andreas Rydberg