JPEGs have 40 frames?

[Barry Levine]

I'm using QT Player objects to hold (referenced) jpegs or movies. The 
user makes this choice so the Player is required. I've noticed that 
when I reference a jpeg, the property inspector says it has 40 frames 
and I can actually change the currentTime in the property inspector 
from 0 up to 40. Is this a bug or is there something about jpegs I 
don't understand?

Regards,
Barry