torque launchs more jobs than number of virtual proc per node

Hi all,

I have installed torque 2.1.0p0 on 20 dual socket dual-core nodes, and using 
pbs_sched. in my nodes files i have specified:

node1 np=4
node2 np=4
.
.
node20 np=4

All my jobs are single process jobs that needs to run on one core/virtual 
processor, and tend to finish about the same time. I can't get torque to stop 
launching just 4 jobs per node. If my queue is not full, this seems to work; 
but if I have, say, 300 jobs in the queue, with majority of the jobs queued up 
behind the first "wave" of jobs, some of the jobs from the 2nd "wave" would 
launch as many as 8 jobs on a single node, therefore substantially slowing down 
all the jobs on this node. When I try to set $max_load in the mom_priv/config 
(tried to set at 3.5), the nodes gets the job-exclusive,busy state, but would 
still continue to take on jobs. It seems like, once there are jobs queued up, 
torque no longer check each node's state before launching more jobs to it...

I've read posts similar (not exactly same behavior) to this, and a recompile of 
torque without optimization helped. I just ran ./configure and make - where 
should I take out the optimization?

Would using the maui scheduler (instead of pbs_sched) help?

any suggestion from the list would be helpful. thanks in advance!

adrian