Multiple flashes on AF360FGZ?

I had recently used the AF360FGZ on my IstD for an indor event and it was able to flash in quick sucession several times. (2x per second for at least three flashes).
Now I was at another event, indoors and outdoors this time, but the flash could barely keep up at one frame per four to six seconds.

Any ideas what might have caused such a change in behavior? Both times a fresh set of the same type of non-rechargable batteries were used.

In a recent thread someone mentioned using a higher ISO, but I would think outdoor phtotos needing a -2 fill flash would drain a less power than indoor shots.

Amy I incorrect, or is there perhaps some other setting I may have inadvertantly changed that would affect the behavior?

It sounds like it has been discharging completely. Four to six seconds is about as long as it takes to charge from a full discharge.
The discharge required is a combination of ambient light vs distance. Being outdoors helps, but don't forget the inverse-square law : that is, that if a subject is twice as far away it requires four times as much light.

The other thing is the P-TTL mode. It requires twice as much power - one flash for the preflash, and the same for the main flash. Combining this with the inverse square law you end up with some serious drain!

Maybe you were just stretching it too far?

If you are in a fairly controlled setup, you can switch to manual on the camera, then change the mode to M or A on the AF360. This will give you twice as much power because there's no preflash.

Obviously I can't give a complete answer (as I don't know the exact circumstances), but hopefully that's given some food for thought!
Matt