You could try just moving them out of the Knoll folder.
Might work.
Are you sure you downloaded the correct version the Knoll products? I think the AE5.5 versions for OS10 were written differently.
bogiesan
Maybe try resetting your AE Prefs? Hold down the Command key when you double click AE.
Try a Get Info on the individual plugin files to see what application they've been designated to open into?
Man, we're totally guessing here!
If all else fails, try calling the publisher.
bogiesan
Maybe you should upgrade to Light Factory 2 and AE 5.5? (or AE 6 in a few weeks)