R help - Jun 2006 - rJava: java.lang.OutOfMemoryError

Hi,
Has anybody encountered the following problem?
TIA, Gregoire
> library(rJava)
> .jinit()
Error occurred during initialization of VM
java.lang.OutOfMemoryError: unable to create new native thread

This would not help:
> .jinit(parameters=c("-Xmx512m","-Xmx128m"))
R and rJava versions are:
> installed.packages()["rJava",]
                Package                 LibPath                 Version
                "rJava"    "/home/user/lib/R"               
"0.4-3"
               Priority                  Bundle                Contains
                     NA                      NA                      NA
                Depends                Suggests                 Imports
"R (>= 2.0.0), methods"                      NA                    
NA
                  Built
                "2.3.1"
> R.Version()
$platform
[...]
$system
[1] "i686, linux-gnu"
[...]
$version.string
[1] "Version 2.3.1 (2006-06-01)"