frustrating memory anomaly

Hi,

Configuration:

OS - OS X server 10.3.8
CPU - dual 1.8
RAM - 3 gig
WO - 5.2 or greater

I have an app that fails in deployment (becoming unavailable in the 
middle of a transaction) that does not fail while testing the same 
scenario in development.  This happens while downloading a rather large 
data set to a file.  The deployed memory settings are -Xms256m 
-Xmx1800m.  Now, even though this is a large data set, it is virtually 
impossible for it to be greater than 1.8 gig.  This is a raw row fetch 
from 1 table, no joins.  Meanwhile the whole database in an oracle dump 
is only 2.16 gig.  So my question is, how do I know for sure that 
Monitor is really claiming the specified java heap settings?  I can see 
it in the 'current settings' block on the configuration page, but I am 
skeptical for the reason I already outlined.  Any suggestions?

Thanks,

--Brian