This mod was done by my dealer and explained to me. Please excuse me if I am using the wrong terms.
Plug in your trailer with an extension cord so you can manually plug and unplug the trailer from the curb side. Run your fridge on A/C for at least 3 hours.
When ready, locate your outside fridge access panel. Take a quarter or a large blade flat screwdriver and turn the 2 clips 90 degrees to make the slots vertical.
Now put your fingers in the top slot and pull towards you to unclip the panel. The fridge drain hose may be squeezed into a panel vent. I just let mine hang but you can also easily pull it out for easier access.
Remove the heat shield in the bottom right corner by removing the four screws highlighted in the pic.
Look for the a little metal circle at the bottom right of the chimney and move it so you can see inside:
Look inside carefully and you will see what looks like a copper wire. That is the ignitor. It works by sending a high voltage through a wire close to the propane rail. The electricity grounds to the rail and the resulting spark ignites the gas.
The working theory is that initial gas delivery may be weak after sitting for an extended period of time due to gas dissipation and air or other contaminants rising to the top of the tube and diluting the gas. The idea is to move the ignitor to the part of the LP rail that is diffusing the most gas.
Before doing anything, it is critical we do a baseline test to see if we are accomplishing anything.
While looking in the hole, unplug the fridge from the extension and count the number of clicks required to ignite. In your case it may not ignite, the point is to count the clicks. As soon as it stops clicking, plug the fridge back in to shut off the gas.
Make sure everything has cooled enough and using whatever is handy, bend the tip of the wire so that it looks like mine. The idea is to get the tip to be on top of the gas rail so it is closer to the gas flow. Not too close, but close enough. If you are too far apart the spark will not jump, too close and it will be small, reducing the ignition potential. You essentially want a nice big fat spark.
All though extremely unlikely, we may as well check that the propane nozzle is not misaligned.
The gap (highlighted by the green box) between the gas nozzle and your chimney should be around 1/4".
If you need to move the nozzle closer to the chimney, loosen the 2 screws shown in the next pic to advance it. Be sure to tighten after the correct gap is set.
Also check that the nozzle lines up perfectly with the hole. If it is at an angle you can bend the bracket slightly to line them up.
Leave everything as is and unplug the trailer while looking in the hole. If everything is good, it should ignite in 1 or 2 clicks. Don't forget to close the little door before putting the heat shield back on.
You may also want to take this opportunity to attach some screening material to the access panel vent holes to keeps insects out.
Let me know how it works out!
I, too, have bookmarked it. 
