Subtitler:I have a 24p project which will be shown at television PAL

I have a 24p project which will be shown at television PAL. How can i be sure that my spotted titles will be in sync on the television program?

If you put your subtitles inside the editing system, then there is no problem. Export as Quicktime 24p, set the framerate in subtitler to 24, spot, export and import the titles into the editing system.
The situation gets more complicated if you need to export an EBU (.stl) file. EBU does not support a framerate of 24, and the program in PAL will run 4% faster. You cannot simply set the framerate in subtitler to 25, because the movie in Subtitler always runs at 100%. This leaves you with three solutions:

This problem does not concern NTSC users. While the framerate 24 and 30 is different, the speed is still the same (if 24p is actually 23.976). If you encounter a problem, consider spotting the pulldown version of the film.