Quote: "AGK auto assigns Sprite ID's from 10000. So unless you are assigning Sprite ID's manually all Sprite ID's would be > 5."
This is not quite true.
There are two methods of assigning sprite ID's. The first is automatic:
spriteID = createSprite(imageID)
An ID over 10000 will be assigned to the spriteID variable, this ID could also be assigned to an array:
array[number] = createSprite(imageID)
The second method is hard coded:
createSprite(1,imageID)
This creates a sprite with an ID of "1" but of course any number can be used.
Generally it is better practice to assign an automatic ID and track ID's correctly in your code but if you have a simple game you might find it easier to use hard coded values for simplicity in reading your code.
EDIT: Ninja'd by Hodgey!! I've been away too long
EDIT2: Actually Hodgey the values go up from 10000