Purging all thumbnails from ADE

I have ADE 1.75 and it is a great product...thanks for the hard work!

However, I built my own set of objects and placed them in a single BGL library. I created thumbnails from modelconverterx and placed them into the ADE 175/FSX/thumbs folder and it works fine. It shows images on the "tool tip" and on the LOM display. However, I had to change the models, regenerate the BGL library and recreate the thumbs file. My problem is the LOM and the 'tool tip' still show the old model. All the thumbs with that old model were deleted from the thumbs folder and replaced with the new ones when the library was rebuilt.

I tried deleting the object library from ADE, saving, exiting and reentering ADE and checked the library was gone in LOM. I reloaded the OBJ into LOM but the old thumbs still appear. I also tried pointing the thumbs location in ADE to another place, saving and exiting and then restarting. It still has the old thumbs.

I understand from other posts that ADE apparently builds a working file that has all the thumbs you look at. That way it doesn't have to search thousands of thumbs every time you look at an object. Apparently that file persists even if you load new thumbs and even if you delete the old ones thumbs in the thumbs folder. So my question is, how can I "purge" this "working index" of thumbs that ADE apparently has in it?

I know I could scapture new thumbnails or point to them one by one but there are many, many in the library.

Anyone help?