Thanks Spikeyxxx, you have solved everything. I just KNEW that somewhere along the line it was down to me being a numpty. I had no idea that you had to select the keys and not just the curve. I suspect that because I’m often only selecting one curve at a time I have keys selected by virtue of the last operation when I turn to the graph editor. That would explain why some curves went linear and not others. The other possibility is that when I clicked on a given parameter in the Graph Editor I accidentally changed the spanner from grey to white. Knowing me both mistakes were made! Mind you I’ll forgive myself for not knowing about the spanners, as it’s not exactly intuitive as to whether they are on or off and even what they do. The hover info just says ‘F curve modifiers disabled’ whether they are grey or white. What the heck is a F curve modifier anyway? Is that the interpolation control? Anyway, thanks for your help. At least I can change from Bezier to Linear now! Cheers!
