iPhoto books question

Im making a book on iPhoto, and sometimes when I add pictures, there comes a yellow triangle with a black excelmation point on some of the pictures, anyone know what this mean? I cant find it anywhere.

And anyone have any experience with the iPhoto books that would like to comment?

It means that the resolution is very low and that the resulting print might not be very good quality.

I just got one iPhoto Book made: I used a google map for the back cover and I got that icon. I went into Photoshop, made the rez higher and it was ok after that.

Nice feature that warning they have, I might add.

ooh okey, Great thanks! Do you think you could take pictures of your book so I can see? is the quality good?

The quality is outstanding. I was afraid when I submitted the photos/iPhoto book, there I was worrying about colour space on my monitor vs colour space in printing and it turned out better than what I thought would be ideal.

There is just one photo I feel that looks a bit off in the colour balance but that could very well be the photo I sent, will have to check it out.

Have a read of Mathogre's exelent thread on his iPhoto book
http://www.mac-forums.com/forums/showthread.php?t=78240