lots of apache "httpsd" processes in "sbwait"

[Chad Leigh -- Shire.Net LLC]

I have several installations of apache running on a FreeBSD 4.9 system 
(soon to be replaced with a 5.3 system).  One particular one, a 1.3.27 
plus Ben-SSL, with PHP,  has a LOT of its processes in "sbwait" state.  
I have been googling and did not find much that explained what this was 
symptomatic of.  One from Terry Lambert had some interesting info, but 
this system is not that highly loaded and based on the clientele of the 
site, I would expect that they are all on high speed links (a video 
gaming site -- mlgpro.com), and he had mentioned that this might be 
from slow clients.

Could this be a symptom of a denial of service attack?

What does it mean (in detail) and are there things I can adjust to make 
it not happen?

Thanks
Chad