EZ CD 5 and Nero 5.0 or 5.5 works fine together. The only thing you should NOT DO IS:
Install Ahead InCD.
Packet CD and Direct CD does not, can not and will not work together aunder any circumstance.
But Nero an EZCD is fine as far as I am concerned atough i do have it installed i dunno why anybody would wanna use ezcd while nero is out there.
Last Night it crashed with an out of memory message on a 512Mb 75GB x2 system with about 90GB free drive spaces

So I would like to congratulate it's engine programmers on creating the most massive code. However be careful with nero since loads of small files and over 10x writing is a lethal combination due to it's cache handling no matter how fast or good your hard drive's are.