Does anyone have problems with airport security and using the bundle packing method? Obviously, your bundle is going to be disturbed if someone feels the need to search your bag. Any other problems?

One thing you can do instead is to pack using the little zip-pouches with see-through tops from Eagle Creek or Rick Steves. TravelSmith sells them here:
http://www.travelsmith.com/jump.jsp?itemID=335&itemType=CATEGORY&path=1%2C2%2C252%2C335

I've had my bags searched several times by TSA (usually when bringing back chocolate, which I've been told looks like C-4 in the scanner). I've found that it isn't a problem to bundle pack.

Ususally the TSA agent has spotted an item/area in your bag that looks suspicious. They ususally head for that area of the bag. It is therefore important to keep non-clothing items separate from your bundle so the TSA agent can see it. I use an Eagle Creek half tube for my electronics, I keep my ditty bag on top. Other things are tucked in the corners. But the bundle (located in the middle of my bag) only contain a small plastic skirt hanger, socks, undies, scarves, clothes. It looks clean on the x-ray which is why I suspect it is undisturbed.

I appreciate all of your advice so far about the bundle packing and the garment bag suggestions. Since I am trying to avoid buying a new garment bag, I did a test run of my possible bundle last week. After several hours of sliding around in my trunk, I have learned that I need a much more compact core, but the item I was most worried about came through mostly unwrinkled. I will try it again soon.