Command+F switches to Flex View, where you can set the appropriate Flex mode per track. Make sure you choose the right mode, e.g. slicing for drums, but monophonic for bass, etc.
Using the Marquee tool on an area will automatically set three Flex Markers. Generally make sure you make three markers or grab a middle marker somewhere or you'll be adjusting a larger or different area than expected.
I'm guessing you were originally using just the Flex Tool, from the toolbox.
No need to delete this thread.
PS. Flex editing is probably one of the only things in Logic where you should definitely read the manual. Here you go: http://documentation.apple.com/en/lo...0%26tasks=true
Takes about 15 minutes to complete, but it'll save you a lot of trouble.