Volume and pan automation jumps

Hi, I have experienced the same problem on two different PT 7.0 machines, but unable to find any info in the answer base about it. When using the mouse to edit automations sometimes if I add a discreet jump up or down to a different volume, the volume changes but after a half a second or so jumps up to what sounds like max volume. The levels on the individual track look fine but in the master the volume jumps up. The only way I have found to get around it is by fading up or down rather than discreet volume changes. It's becoming a pain though. Anyone else experienced this, and how do I fix it? Thanks, Rog

Can no one help me with this - Here's another account from a friend with the same prob: "Don't know if this is a bug with pro-tools 7 or not, volume and pan automation is very erratic. No automation present ontrack but it still pans and also changes volume dramatically all over the session." I've seen this on a Dell Inspiron Laptop, and a Dell Precision 380, and had more reports of the same thing from another friend. The same Precision 380 setup runs previous versions of PT fine. This seems like a common bug as I've now seen it on three machines.

Is this possibly a corrupted session? Does this happen in every session? Have you tried all the steps in the thread?