Bicycle Mechanics - Chain gets jammed between front chainring and chain guard

I have a problem that happens sometimes when I shift into the smaller rear cogs. The lateral vibrations from jumping down to the smaller cog sometimes causes the chain at the front chain ring to catch the tips of the ring and makes it ways between the front chain ring and the chain guard ring. The chain ends up jammed in between them so I have to pry them back out sometimes.

The chain doesn't fall inward because I have a chain guard there too. If the outer chain guard wasn't there, the chain would simply fall off. Any ideas on how to fix it?

I tried taking some links out of the chain to increase the chain tension but that didn't seem to make a difference.

Here's a picutre... http://i1103.photobucket.com/albums/g465/adamtki/Unknown.png

adjust the limiting screws on your front der?

A few things you might clarify for others: Is there only one ring upfront? How many cogs out back? Was this a factory drivetrain or did you build/modify this bike into its current
configuration?

A few things you might clarify for others: Is there only one ring upfront? How many cogs out back? Was this a factory drivetrain or did you build/modify this bike into its current
configuration?

There's only one ring in the front -- no front derailleur. Rear has 8 cogs. The problem usually happens when shifting to a smaller cog from around gear 3 (3rd largest). This is a factory drivetrain (Dahon Mu P8 folding bicycle). I didn't modify the drivetrain (other than to try to fix the issue by removing two chain links). The problem has always existed.

adjust the limiting screws on your front der?

Maybe you posted before I added the picture, but you can see that there's no front derailleur in the pic.