FYI for future reference:  After using Fantastico to upgrade phplist, I rec'd this error message in the error log after getting a 500 Internal Error:

Invalid command 'php_flag', perhaps mis-spelled or defined by a module not included in the server configuration

You'll need to remove this line from the .htaccess file in the directory that you have phplist installed:

php_flag magic_quotes_gpc on

It looks like this is automatically added to the upgrade installation.

I agree. Thanks for the info.

I just updated to the newest stable phplist release 2.10.7 and with every single upgrade I've ever done for this package, it was a hot mess. I've updated multiple php script packages (WordPress, LimeSurvey, SMF, etc.) and I've never had a package give me such permissions problems. It looks like when you manually update the package, the .htaccess fix noted above is already there so that's one less thing to worry about.

However, for some reason, the permissions all the files I uploaded were set to 664 and the folders to 775. If you've got an index.php file with a 664, you generally get an 500 Internal Server Error. Make sure the permissions on index.php in the phplist root directory and the phplist admin directory are 644 and you should be fine.

I spent far too much time last night changing all the permissions just in case. That's 2 hours of my life I won't get back.