You might want to peek inside, with you favourite zipper.
It could be that it uncompresses all class-files for speed-reasons, but that's a totally wild guess. (And it would require the whole JAR to be rebuilt... maybe the reason of the minutes delay?
Nah... just compare the jars and work from there.
I would like to compare the Java archive but I don't find where Java hides the downloaded archive. I looked into ~/.java/deployment and I didn't find it.
There are now exactly 128 class files inside my game.