question about putting subtitles into avi

[pike8]

i have a standalone DVD player samsung P360. it's really great, except when i play .avi/.divx movies with .srt/.txt/.sub subtitles - they are too small.
so, i decided to "stick" subtitles on my movies. i tried many softwares, but only one that did the job (and did it fast) was srt2bmp. i had two tv shows (black adder & ofah); i added the titles to all the episodes, burned them to discs, but when i play discs on my player, only black adder has titles, ofah don't. what could be the problem?

if you can suggest some better software, go ahead.

[Baldrick]

Tried Sub2DivX or AViSub?

[pike8]

yes, when i mux them with avisub, they can't run on my player at all; sub2divx is great, but the subtitles aren't visible on my tv (only the top of subtitles), i tried changing the vertical position, but the result is always the same