Bookmarklets not working on FireFox

Firefox ver. 7.0.1
Mac OS X ver. 10.6.8
DEVONthink Pro Office ver. 2.3

I have the bookmarklets installed in my FF browser. When I use the FF version of the “Clip To DEVONthink” I get a pop-up window that is called “Opening Clip tp DEVONthink.xpi” and the text says 'you have chosen to open…… Would you like to save this file?" the options given are “Cancel” and “Save File”

Any idea how I can make this work?

Additionally, when I try a different bookmarklet, such as Bookmark, I get a blank screen for a while, then tons of tabs open upm none of them with any useful info, and I end up force quitting FireFox.

Any suggestions on this one?