Slow directory access with lots of files

[Totem]

Hello,

I'm new to this list so please excuse me if this has been asked before 
or if I don't provide enough info.

I'm having an issue and I hope someone can help me understand what is 
happening.  I have a FreeBSD server that is running Samba.  When users 
access directories that store lots of files (3k or so), access to the 
files is very slow.  I'm guessing that it is a file system issue.  I'd 
like to troubleshoot the problem but I don't know where to start.  (In 
the mean time I have just told the users to create sub-directories and 
sort their files).  Is there anything that I can do to make things run 
faster?

Here is my OS version:

# uname -a
FreeBSD server.example.com 5.2.1-RELEASE FreeBSD 5.2.1-RELEASE #0: Mon 
Feb 23 20:45:55 GMT 2004     
root at wv1u.btc.adaptec.com:/usr/obj/usr/src/sys/GENERIC  i386

Here is some of the software used by the users to access files 
(installed via ports):
samba-3.0.4,1
nss_ldap-1.204_5
openldap-server-2.1.30
(plenty of others)

I'm using POSIX ACL's on the files/directories that are slow.  User 
account information is stored in LDAP.  The server is a fast enough, 
uses RAID 5 w/ SCSI drives, and there is plenty of RAM.  Utilization is 
fairly low so I don't think it is a HW problem.

I'm going to update the OS and ports on this server soon.  Perhaps that 
will help, but I'm not too hopeful.

Any thoughts? 

Thanks,

Totem