SMP active?

[Gardell, Steven]

I am running Erlang on a 4 Core Dell machine:
 
Linux xxx.sonusnet.com 2.6.9-55.ELsmp #1 SMP Fri Apr 20 16:36:54 EDT
2007 x86_64 x86_64 x86_64 GNU/Linux

Erlang R13B04 (erts-5.7.5) [source] [64-bit] [smp:4:4] [rq:4]
[async-threads:0] [hipe] [kernel-poll:false]

When I run my Erlang program  (a Megaco test program), top shows only 
only one of the cores being used to any meaningful level. Something 
like (5%, 97%, 97%, 97%) idle. Push it harder and, not too surprisingly,
it starts presenting errors. I have tried the -smp and -S options, but
there is 
no change in behavior (which is consistent with documentation, since smp
should
be enabled by default).
 
Suggestions? Thanks!