The acess to Adempiere through WebStart used to be very slow in my environment. Each time I need to open a new Window takes about 30 to 50 seconds before showing anything. After some debugging, I discovered that WebStart Adempiere Aplication tries to fetch a file named "Adempiere1.jar" from server, which does not exist.

I've discovered that in the build.xml used in setup it creates a temp file with this name, which is renamed "Adempiere.jar" later. But as in the build process was configured to generate the index in the JAR file (index = "yes"), the file INDEX.LIST Jar file references the file "Adempiere1.jar," causing the problem.

As far as I researched, the index would only serve to accelerate the location of classes, but as in this case it points to the wrong file it ends up generating this delay. Even large files from java platform, such as rt.jar, use this feature.

I have attached a modified version of the build.xml (and a diff file) which disables the indexing of the Jar file, which solved the problem of slowness and has not presented side problems in my tests.