1.0 builds and monster spawning?

I've been running dev builds of 1.0/1.0.1 for a while now and today switched to the RB of 1.0 server. For some time I've had a problem with hostiles not spawning (animals spawn fine as do mobs from mob spawners underground). If I'm 'lucky' maybe a 1-3 mobs spawn in a game weeks time and that is maximum. Configuration is correct afaik and I've tried to remove all plugins to see if that affected spawning with no result.
Anyone know how to fix this and have the hostile mobs spawn again?
Any advice on tracking this down or how to fix it would be welcome.

 

This isn't the right place to post. Next time post it in a more appropriate forum, like Bukkit Help.

Have you /butcher 'd the mods then waited for them to re-spawn ?

 

My bad, can moderator please move this to the appropriate subforum?
No, no butchering, actually never seen references to such a command.

 

It's a part of plugins such as command book, essentials etc. WorldEdit

 

Ah, thanks, I do have CommandBook installed. Googling though it seems I'm not alone with this problem and all states it started somewhere along the line of Dev builds where they stopped spawning from one build to next and then never came back (guess that makes it at least partly feedback/bug report).

ed: Looked through CommandBook command list and found no such thing.

 

It's a part of WorldEdit.

 

Still though, butchering mobs won't do much if there are no mobs to butcher to start with. If we are severall people online 1-2 MIGHT spawn which makes me think that maybe spawning is working technically, just that somewhere the spawn ratio is WAAAAY off.