duplicate programs listed in "Open With" menu

Whenever I control-click a file and want to select "Open With", there are duplicate programs listed. For example, if I want to open an AIFF file, QuickTime 7.6.2 shows up twice in the list along with iTunes, WaveBurner (a Logic Pro program) and other programs all showing up twice. Even another version of QuickTime (6.0.3) is listed.

Anyone else have ing this problem? Anyone know how to fix it? Thanks