hmm…
maybe i just got lucky? i’m using cs4 as well. did you use shortcuts? i didn’t, maybe that could help.
you’re not clicking anything in the timeline right?
i clicked the sequence name in the project tab, then clicked edit, copy from the toolbar. i didn’t close the project but just clicked open new project. it opened a new window and i simply clicked edit, paste and it was there unlinked.
sorry if this doesn’t work for you!