If you're going to pace someone over a jump, make sure you know that *they* know what they're doing!
A month or two ago I went out for the first time in a long time on a track that looked rather tame with safe, rounded landings (Durhamtown Plantation). I pulled out onto the track behind three guys who were jumping everything so I just followed them over. About halfway through the first lap the lead guy started to pull away so I passed the other two to ride with him. The jumps are very safe and rounded, but many are blind. We hit one and I watched the guy I'm following case the triple. I was still in the air and already cussing him because I knew what *I* was going to do! I cased it, but didn't crash (he didn't either). I quit following him at that point.
Another thing to consider when following someone over a jump is that following directly behind them means if they crash, you probably will, too. I usually follow off to the side, but then you run the danger of the takeoff (and landing) being different on different ides of the jump.
On a related note: Once you start jumping somthing, jump it every lap (unless something goes wrong on the approach). If you only jump something half the time, *every* time you come up to it you will be hesitant and more likely to screw up by changing your mind at the last second. if you know you can do it, commit to it and you'll be much more likely to safely jump it. Obviously if you miss a gear or lose traction out of the preceding turn or something else goes wrong, it is better to not jump it under those circumstances, but being unsure and making a last second decision to abort will likely cause you more trouble than confidently committing to something.