Specifying the size of a page in Pages
I am trying to design a small document on Pages. I would like to set the page size to 8.7 x 5.7 centimeters. I have tried the menu "File > Page Setup > Paper Size > Manage Custom Sizes"; here, I have set 8.7 cm x 5.7 cm, I have set the margins to 0 and I have given a name to this new format. Then I click on "OK", I am back to the page setup window pane, my new format is selected, so I click on "OK" again.
But, when I go back to my original document, the page size is set back to A4. It is driving me crazy. I can set it to many different formats, including A5, C4, C5, US Letter, etc, but not my small 8.7x5.7. Why not?
Thank you for your help.
MacBook (First model), Mac OS X (10.4.9), I also have a MacMini (Intel core duo)