Debian Sarge, PHP4 and Apache2.. why do you persecute me?

Oh FFS! Has anyone had a problem with Apache2 and PHP4 on Debian Sarge/Testing? I have a stock install of it with nothing unusual AFAICT but Firefox keeps trying to download and save php files instead of processing them. All the config files seem to be correctly set up. Files in mods-enabled/ are fine.
Why am I upset? I added the wp-newblog.php to WPMU SVN tonight, imported a chunk of code from install.php so it’s a one-step process, but I can’t test this thing to see if it works! It’s here as a WPMU snapshot but it won’t work out of the box. It needs an entry in .htaccess first, and bug fixing.

I’m off to relax, it’s been a long day.. zzzz

Much Later… I finally got it working again. I tried dpkg-reconfigure phpmyadmin but it didn’t update the config file with this error:

Not replacing deleted config file /etc/apache2/conf.d/phpmyadmin.conf

Following the clues from here I did the following:

apt-get remove –purge libapache2-mod-php4
apt-get remove –purge apache2
apt-get install libapache2-mod-php4 phpmyadmin

PHPMyAdmin now works fine, and hopefully wpmu will too!