I run 9 customs in my rotation and have no problems, but adding the same map more than once will screw things. It puts the server into a "loop", so the server dosne't know which map is next it just cycles back.
I have had 20 or more maps in rotation with no problems, but have seen a custom map mess it up. If you are running a dedicated server the error code will still be on the console. What does it say? Try changing the order of the maps to see if you can isolate the problem map.
**Practicing the dark art of turn signal usage since 1976.**
This is pretty much all I get on the console ... then it just re-runs:
------ Server Initialization ------
Server: dm/mohdm1
==== CleanupGame ====
Adding script: 'dm/mohdm1_precache.scr'
-------------------- Spawning Entities -----------------------
soundtrack switched to .
^~^~^ Event 'sunflare' does not exist.
^~^~^ Failed execution of event for class 'World'
-------------------- Actual Spawning Entities -----------------------
-------------------- Actual Spawning Entities Done ------------------ 15 ms
0 teams with 0 entities
Adding script: 'dm/mohdm1.scr'
Adding autosave names
33 entities spawned
94 simple entities spawned
0 entities inhibited
-------------------- Spawning Entities Done ------------------ 24 ms
Going from CS_PRIMED to CS_ACTIVE for Chippy
Chippy has entered the battle
------ Server Initialization Complete ------ 0.39 seconds
soundtrack switched to music/mohdm1.mus.
playing music/mohdm1.mus
music set to normal with fallback normal
Loading Ambient.scr