Outer Limits 4x4 Board

I have a 2008 JK Wrangler Unlimited CRD Auto, and sometimes when I go to start it, the car wont even crank over, all lights and radio and dash working just wont crank over.
It is very erratic, sometimes it wont do it for a few weeks than all of a sudden it will happen a couple of times in one day, there seems to be no pattern such as a cold engine or cold weather or warm weather... Its got me stumped.
Anyone else have this issue?

start simple... check the switch on the auto that only lets the car start in P or N, it sounds very much like that kind of thing.

When it is doing this does the stereo turn off when you turn it all the way around to START? If it doesn't then it is not receiving any instruction to Start and it might be worth looking closer into the ignition barrel. If the stereo turns off then the ignition barrel is most likely doing it's job.

Check your battery is healthy and the top of it isn't going wobbly/bubbly. The Optimas fitted to these vehicles do not last long for some reason and when they start to die they cause all sorts of epic random issues. Failing that book it in for a software update at the dealer as there are a few starting bugs solved by an update.

Thanks for the feedback guys, again it happened over the weekend, thankfully it only took a few minutes for it to start...
Found this offical service bulletin online over weekend and based on this I pretty sure this is the issue, I guess I will need to take this back to the Jeep service centre to get fixed.
http://project-jk.com/images/tsb/TSB_08-007-08-REVA.pdf" onclick="window.open(this.href);return false;
Unfortunately the car ran out of warrenty 3 weeks ago, and I even had the car in for an end of warrenty check about 4 weeks ago. Hopefully the service centre will be reasonable and fix this under warrenty considering it is a know issue and wasnt picked up in the end of warrenty vehcile check.