I am running Photo Mechanic 4.6.3 on Mac OS X 10.5.8 Quad-Core Intel
Example - I select 15 jpegs that I want to edit in Photoshop, hit apple E to make them open in Photoshop (i set that up in prefs). It doesn't open them up the first time, I always have to hit apple E again to get them to open. It's only a problem because I usually open a bunch of files in Photoshop like 30-100 and it's going to take a minute so I go back to Mail or Safari or whatever while it process, but then when I'm ready to work I go back to Photo Mechanic only to find out it didn't open any, so I hit it again and it works fine.