having encountered the same problem, i did some research myself and might be able to shed some more light on this topic: the problem seems to be related to the introduction of input-hotplug for X11 in Intrepid (see ). Further, roaming through a couple of Ubuntu forums, I found that there were people facing more severe side effects than just /dev/input/* having no output, such as no working keyboard at all, etc. There are some suggested workarounds for their problems too, one of which worked for me: put
Option "AutoAddDevices" "false"
into the "ServerFlags" section of your xorg.conf and restart the X server. Voila: cat /dev/input/* reflects mouse movements again and JInput correctly reads those values as well.
Honestly, being a total nitwit in terms of X11, I don't even know what this setting really effects. It's just something I found out and wanted to share with anybody who might be able to address the problem properly and could benefit from this information (and anybody who, just like me, can continue developing for the time being).
Needless to say, that this can only be a short-term, dev-only workaround for me, as it can't be expected of any normal user or customer to change some system-config (leaving aside any necessary chmods on /dev/input/*). Therefore I would very much appretiate any solution that works with standard-Intrepid and standard-JInput - whatever needs to be changed for that. Yeah, needless to say...
PS: Having just started with JInput today and being new to JGO as well let me please say hello and thank you for the wonderful Jinput API!