I cannot see my authored subtitle

Hi. I'm just beginning to make some DVD authoring, ans I'm stuck with this issue.
I have both an english movie and its subtitle, in .SRT format. Since english is not my native tongue, I wished to add a selectable english subtitle to the DVD, so the movie's comprehension becomes much easier.
I read hundreda of tutorials, I learned that one could convert the .SRT to .SUP format and author the M2V, the audio stream abd the .SUP. I made it and authored the image with ReJig.
The problem is that the movie is perfect, I can select the english subtitle but nothing displays on screen.
If I try to rip the subtitle with SubRip it appears perfectly (only, it is strange because the subtitle appears blue in a black landscape) , but I cannot make it appear in the movie.
Did I use a wron authoing application? Or what?
Please note: in SrtSup, as 'global settings' I used Background: black trasparent, Text: white, all other colors: silver.
I 'Unchecked Use Default Target' and placed the subtitle at: X1=100 (left), Y1 (top)=470. Vertical alignement: bottom, Horizontal alignement: left.
Screen format = PAL 720 x 576 (25 fps), since y system is PAL.
What did I do wrong?

Thanks...