Very Slow Run Time on AS/400 for Java Program

Hi,

I put my question out on JGuru but got no replies so hopefully you can help
me out here.  I wrote a Java program to Select records (by certain fields)
from an AS/400 file, Delete from an Sql Server table, and then Insert the
selected records to this Sql Server table.
My environment is:  OS/400 V4R5, JDK 1.3, Native JDBC driver (from AS/400
Developer Kit for Java).  I am using the latest versions of the db2_classes
(AS/400), and msbase, msutil and mssqlserver (MS Sql Server) jar files in my
classpath.  I used QSH javac to create the class for my Java program.  I
then did a CRTJVAPGM at optimization=40 for this class, as well as the 3 MS
Sql Server jar files (I got "unable to create" error when I tried the
CRTJVAPGM on the AS/400 jar file).  I am using blocked fetch (set the block
size to 570, which is a multiple of the total length of my fields), and
batch update (using addBatch and executeBatch instead of executeUpdate in my
results loop) - both of these coding logic were ones that I found in a JDBC
performance tips document.
The problem is that  the Java program runs VERY slowly on the AS/400 (either
from QSH with java, or with RUNJVA) and uses up alot of CPU resources.  It
runs well over 10 times longer than if I ran it from the PC DOC environment.
Any suggestions on what could be causing such poor performance when running
the Java program on the AS/400?  I have scanned many Java/400 forums and
websites but am just about out of ideas on what to try next.  My Java
program is virtually useless the way it runs now on the AS/400.  Please
help!
Thanks alot!