Patching over a seam is tough. It's possible that it just wasn't going to happen... but things I do are sand the seam extra to try to bring it closer to the level of the rest of the tube ... and be extra careful that there isn't a glob of wet glue up against the seam when I apply the patch.
ETA - I missed that you used a self-stick patch. I don't have a lot of experience with those, but I've heard they're not as reliable. I carry them for on-the-road repairs, but if I have the luxury of mounting a spare tube and patching the hole at home, I use the kind with the separate rubber cement.
Last edited by OakLeaf; 05-31-2010 at 06:22 AM.
Speed comes from what you put behind you. - Judi Ketteler