In the case where my favicons get washed out, this is the easiest method I've found to get them back:

Preparation:

a) Have Firefox set up with XMarks, but disable it.

b) Have Chrome set up to sync bookmarks but disable it.

c) Install XMarks for Chrome.

Now when disaster strikes and all your favicons disappear:

Enable Chrome bookmark sync. You end up with dupes, but you get
your favicons back.

Disable Chrome bookmark sync.

Bring up Firefox and enable XMarks.
Upload your Firefox bookmarks.
Disable XMarks and close Firefox.

In Chrome use XMarks to Download bookmarks.
Now you have in Chrome all the bookmarks you had in
Firefox with the favicons.

Only hassle is you can't use XMarks to sync both Firefox and
Chrome on and ongoing basis or you get into a loop with mucho
dupes. So you need some method to keep your Firefox bookmarks
up to date.

Flawed, but still better than manually deleting dupes.

edit: otoh if we could just get the CheckPlaces author to write a Chrome extension, that would
kill the dupes auto-magically. Then we could side-step the XMarks on the Chrome side.

edit2: an alternative to manually adding bookmarks to FF would be to use XMarks to download
all your Chrome bookmarks. You get the dupes, but just use CheckPlaces to delete the dupes and
refresh the favicons. Maybe once a week or something would be worth doing.

Still, I hope somebody comes up with something simpler.

Dev. v. 7.x seems to work with LastPass again. It doesn't kill my favicons. Although the above procedure is good to keep as a ref. since these things tend to go in and out over time.