Thanks for the reply.
I tried it, but there's still no subtitle.
I deleted VobSub in Windows and the subtitles still display correctly in VLC, I guess VLC has its own filters.
By the way, I'm using version 0.8.1 on both Linux and Windows.
I also tried a .sub file and it worked in both Linux and Windows, and other .srt files don't work neither.
Could it be a bug?