yes, all FCP versions before 7 riple the timeline when you do a speed change.
if for some reason a ripple is impossible (audio or video on other tracks getting i hte way)
you get a warning saying there’s a trim conflict.
one solution is to move the clip up to a vacant, or new track.
lock all other tracks, (hold OPTION and click on that track’s lock icon to do this)
do the speed change
unlock al the tracks
another way that i use:
put an in point at the head of the clip.
copy the clip (Apple C)
move to the end of the timeline (hit the “End” key)
paste the clip (Apple V)
do the speed change.
bump the clip up one track (option + up arrow)
cut the clip (Apple X)
go back to the in-point (Shifti i)
and paste
because i bumped the clip up,
it pastes back onto the track above the original clip.
this sounds like a lot more work,
but i find it much faster than locking / unlocking tracks.
ANOTHER approach
match frame the clip into the viewer. (select the clip in the timeline, hit f)
do your speed change IN THE VIEWER,
edit the clip back into the timeline.
problem with this (since FCP5 perhaps?)
is that changing the speed on the match framed clip changes the speed of the BROWSER clip.
not a huge problem when you are aware of it.
nick