addendum to 11/20 bug report Rated 3 out of 5 stars
After much digging and messing around, I have gotten Evernote clipper to work w/FF8. The main culprit, it seems, is the diigo toolbar, which also interferes with joiliprint.
I'm glad to have fixed this up, but in the doing of it, I discovered four (4) working installs of evernote, in nested directories, in various versions. Only one of them appeared in Control Panel > add/remove applications. It appears that Evernote, when installing updates, looks for an evernote directory, walks the tree until it cannot find a directory called 'evernote' and then deposits a new evernote directory, where it installs the latest version. I can't imagine this is intended. Deleting the extra versions seems to have no harmful effect.
I would like to see Evernote Clipper allow the insertion of tags at the time of clipping (as do delicious.com and diiggo.com). The need to open the evernote app after the clipping is somewhat burdonsome.