Package: libapache2-mod-php4
Severity: serious
Justification: breaks upgrades to 2.2 and beyond

libapache2-mod-php4 has a dependency on apache2-mpm-prefork >> 2.0.52. 
The ABI is broken with Apache 2.2, so it should either have a dependency 
on apache2-common (which is called apache2.2-common with Apache 2.2) or 
a << dependency to ensure it's not upgraded to any non-2.0-release.

Oh, and don't bother fixing this before 2.2 hits unstable, but please do 
add the dependency on apache2.2-common then to avoid any such problem in 
the future.

- tfheen