read only on files installed in chrome directory

Hi,

When I'm trying to install a jarfile in my peronal chrome directory with 
an installscript, it refuses
to do so.

When I put it the manually, (with all the rw flags on), re-installing a 
jar-file in my chrome directory succeds, but I can not
re-install again because all the write flags are beeing removed.

This is the a condensed version of th code:
	installRoot = getFolder("Current User");
	chromeDir = getFolder(installRoot, "chrome");
	err = addFile("Installing MlangoCore",  X_VERSION,  "mlango-core.jar", 
   chromeDir,   "",  1);
	if(err != SUCCESS )
	{
		logComment("error adding mlango-core.jar in "+chromeDir+"   err:"+err);
	}

This is the result after the replacemetn has succeed
braas@wunderliebe:~$ ls -lart 
.mozilla/default/oif56zr4.slt/chrome/mlango-core.jar
-r--------    1 braas    braas       12733 May 14 14:43 
.mozilla/default/oif56zr4.slt/chrome/mlango-core.jar

Any suggesions or pointers


Gert-Jan Braas