Tempo bug in 6.1b4

[silicon1138]

I've loaded up a live set that has global tempo changes embedded in the master clips on the right, but i've just inserted a load of new empty scenes in the middle of my main set and for some reason it's not letting me add new tempo automation in the new master clips. The working clips (above and below this new section) show a blue editable tempo line but the new clips only show a grey tempo line and i cannot alter it.
Very odd.
Any thoughts welcomed.
Thanks.