This question has as many answers as people you ask. eZ publish runs fine with all Linux distribution as fare as I know. Personally I run SuSE 9.2 Professional on my laptop to local development On servers I prefer SLES 9 that gives me professional support and security for that the software that I run is really stable and tested for long.
I can also mention that FreeBSD is a great system to run eZ publish on (I'm been installing many hundreds of eZ publish sites on FreeBSD servers). But this is not Linux as you asked about.
Best regards
Egil Fujikawa Nes Fujikawa Engenharia de Software Ltda
BuildCMS - Av. Paulista 777, 15° Andar - CEP: 01311-100 - São Paulo
URL: http://www.buildcms.com
There are no issues whatsoever with FreeBSD and PHP and there have never been any, either. And personally I find FreeBSD to be easier to administer than any Linux distribution but that's also a matter of taste, of course.