I just installed OpenX from the 1-Click today, and as soon as I finished it I got a message that there was a new version available. I had a hell of a time upgrading to the new version, so I thought it might help others if I posted what I did here.
first copy everything from mysite.com/openx/ to mysite.com/openx_backup
then delete everything in the original directory
and untar the update into that directory
now copy the 2 configuration files from mysite.com/openx_backup/var/ to mysite.com/openx/var/.
Both configuration files will have the term "config" in their names. There should be like a default.config.php and a longer-named-file with some portion or all of your website's address in it.
Point your browser to mysite.com/openx to be taken to the install wizard. Go through the agreements and then at the bottom of the check page make sure it says it has detected an older version of OpenX and it can be upgraded.
Then go on to the database page (should already be configured since you are updating). Press continue. You almost definately will get something that says "Failed to upgrade configuration file."
Now go delete the file called UPGRADE which is located at mysite.com/openx/var/UPGRADE
Again, point your browser to mysite.com/openx and you should be logged in to the updated version (I am just hoping this really is completely installed correctly).
Also, on a side note, when I installed OpenX, I did so on a subdomain that was all to itself (e.g. openx.mysite.com) and I was a bit unsure of creating a directory since DreamHost seems to keep all the domains in our home directories and I am not totally sure how DH works. But I went ahead and made the dir and it worked fine.