You've left out perhaps the most significant part of these specs: the OS.
But the standard advice is to make sure the OS is fully patched -- i.e., you've applied all the available patches from the vendor -- and the video drivers are also, similarly, fully patched, and then finally, make sure you're using the latest patch level of the appropriate JDK (1.4 is not very specific -- the very latest version of 1.4 from Sun is 1.4.2_09 .
