Problems with some brushes (PSP)

Hi! This is my first post here. I work with PSP 8. I have some problems when I’ve finished an icon and I want tu add some original border brush. I can’t fix them correctly, I’ve tried with some borders with 1 pix, 2 pix, 3 pix… and with some size (not always 100 but 99, 98, 97) but they never put themselves centered however hard I try to put them inside the icon :(
Here there’s an example:


Thanks!

Lila.