standby mode

[matt]

samba 2.3.3a
redhat 7.3

i have three other computers connected with the redhat 7.3 on a network.  
two windows xp and one windows 98.  the windows computers will go to 
standby fine if not used.  the linux computer will not go to standby, 
something accesses the hard drive about every ten minutes.  if i unplug the 
ethernet cable, the computer goes into standby after a while; when i plug 
it back, the computer wakes with in ten minutes.  then i unchecked the smb 
daemon from the start up and the computer goes into standby.  how do fix 
this to let the computer go into standby?

matt