Hello, We have an application that uses Applets to perform cryptography. Those applets are stored on the client machine. We use Java Plug-In 1.4.2, Windows XP and IE(any version From 5.5). To be sure the Application can crypt huge files we need to set the Java mememory to 512. So we add a line to the deployment.properties javaplugin.jre.params=-Xmx512m (this line is automaticaly added when you specify the -Xmx512m parameter with the Plugin configuration tool) But it appears that on some machines when you try to load any Applet ( on any website with applet) the IE browser closes without any warning. When you change the line and set the memory to 256, it works fine... Now the question: Why? When we used those applets on other platforms they always worked, and they work on many Windows XP machines too... Have someone had the same bug? Is this a "well-known" bug? Thanks.