JME SDK has a bug in linux x86 version, when you try to update, it download the package, install, restart and when you check the updates again, it tries to update the same thing that was update, always. What I do.
try “chmod +x jmonkeyplatform/bin/*”, you seem to use an old installer though, try downloading the new 3.0 installer with JDK 1.7u51 and make sure you install it as the user you run it as.
Problem solved, your solution of give execution permission worked, thanks for the help. I am already using the new version.