http://akmedia.digidesign.com/support/d ... _41784.pdf
To remove a single breakpoint:
With the Pencil tool or any Grabber tool, Altclick
(Windows) or Option-click (Mac) the
breakpoint.
To remove several breakpoints at once:
Use the Selector tool to select a range that
contains the breakpoints, and press Backspace
(Windows) or Delete (Mac).
To remove all automation data of the displayed
type:
Click with the Selector tool in the track and
choose Edit > Select All, then press Backspace
(Windows) or Delete (Mac).
To remove all automation for all automation
playlists on a track:
1 Use the Selector tool to select a range of data
to be removed.
2 Press Start+Backspace (Windows) or Control+
Delete (Mac).
All automation data within the selection is removed
for all automation playlists on that track,
regardless of whether automation is write-enabled
for those controls.