Flash crashing on click "insert target path" button

Well, my computer is still crunching away after clicking on that button. I’ve given it up to 5 minutes to no avail - when I click on the “insert target path” button in the AS panel flash freezes up and the processors work overtime. Both cores are operating at near 60% capacity right now … oh wait, one core took a break and the other is doing all the work for Flash now.

Anyways, this fla has but one imported item, a font from a shared library. When I deleted this item, that button still crashed Flash. I guess I could just go on without using that button, but from my experience in computers and design using a large variety of programs, this is an indication of a deeper problem - and that has me worried, esp since it is probably a problem in this project which I’ve been working on now for over a month. I have a previous version of the file, but using that would throw out an hour or two of work.

Any thoughts?

Update:
I narrowed it down to one of my major movie clips that has about 20 layers in it. From there I narrowed it down to a single row.

Out of all the rows, it is the only one that, when I delete all other rows and leave just it, it crashes Flash (all the other rows by themselves do just fine). But when I restore all the rows and then just delete the one bad row Flash still crashes.

2nd update:
I traced the problem back 25 file revisions - 2 days ago. It seems to occur between two files that are nearly the same. Their library contents are identical, except that the link structure of the bad file seems to have changed quite a bit from the good file. I can’t make heads or tails out of it, but perhaps someone else can. I’ve attached a pic of their target path trees side by side (the bad file will open the target path chooser - it just takes about 30 seconds). Maybe this will help. view flas