In a recent discussion with a friend, he told me he still used JOSM v20080713 because that was the version that was pre-compiled and packaged for his distribution version.

Since old versions have some serious problems with the more recent version of the API, I thought I should write this small note to refer to on future cases.

Installing with a package manager is recommended, so you don't have to worry about dependencies, but once that is done, an update should be made.

- Updating JOSM -

* Download tested or latest version of JOSM (wget http://josm.openstreetmap.de/josm-latest.jar)
* Rename it to josm.jar (mv josm-latest.jar josm.jar)
* Move it to /usr/share/josm (sudo mv josm.jar /usr/share/josm/)