Okay, I found this with a google search; This describes my condition exactly
"2008 Wrangler Unlimited: Will not start after a short drive.
Will not start after a short drive. The starter engages for a very short time then just stops. It has been looked at by the Dealer four times now and still no solution. They have replaced sensors and control modules, no luck. We just went to pick it up from the Dealer [5 Start Dealer] and it wouldn't start. They hooked up the diagnostics computer which showed nothing. with the computer still connected it still would not start and the computer did not help. We kept the key turned to the starting position and the computer showed that that it was in the starting mode and thats it. It acts like a bad battery, however, the battery is OK and ever other electrical device in the vehicle works when the Jeep doesn't start. Sometimes it takes more than thirty  tries before it finally starts. The Dealer does not know what to do."
Answer from a CJD SF;
"Seen this problem before. Here is your solution im the foreman for a jeep dealership.
During cranking/starting, the ignition switch voltage should drop to about 0.4 to 0.5volts and the switch status should show start/crank. If the ignition switch status shows FF, that is an undermined switch status. The ignition switch voltage is supplied by a voltage regulator (5volts) with-in the WCM (WIRELESS CONTROL MODULE). This regulator not only feeds the ignition switch with voltage, but if the vehicle has remote start, it all so powers the WCM antenna. So, items that affect the ignition switch voltage readings would include the power or ground circuits to the WCM, ignition switch and the WCM antenna. The WCM antenna can short and take down the ignition switch voltage. A shorted antenna can cause issues with the WCM functioning properly, i.e. starting and or key programming. Check antenna wire for damage or try and unplug the WCM antenna and recheck the ignition switch voltage.
Take this copy to your dealership and check for radio interference. Good luck with your wrangler got an 08 4 door rubicon I have not had this problem with mine yet. Hope this helps you please rate it."
Then another person added this;
"had the same prob on my 2008 quick fix buy a neg battery cable thats open looped on both ends connect one end to the neg battery post and the other to the bracket holding the alternater. very quick and will sole your problem."
I'm going to try the ground strap idea, can't hurt!
I also plan on looking at the WCM antenna if I can find it but if its shorted that falls on Jeep and they should stand behind it IMHO.