R help - Jun 2009 - RWeka memory problem

Hello,

i get  some memory problems using RWeka and i'm wondering because i have 
only ~ 400MB in RObjects without a high memory consuming
operation when a crash occur.  Look into hs_err_pid.log , it  seems that 
the VM  max heap size is only 512 mb.

VM Arguments:
jvm_args: -Xmx512m vfprintf exit
java_command: <unknown>
Launcher Type: generic

I try to change with  .jinit(classpath=...., parameters="-Xmx1900m") 
with weka.jar and  RWeka.jar in the RWeka lib folder , but i get no 
success?

Many  thanks for a hint.
Regards, Christian

               _                          
platform       i486-pc-linux-gnu  , 3GB       
arch           i486                       
os             linux-gnu                  
system         i486, linux-gnu            
status                                    
major          2                          
minor          9.0                        
year           2009                       
month          04                         
day            17                         
svn rev        48333                      
language       R                          
version.string R version 2.9.0 (2009-04-17)