Problems with subtitles

[boneless]

I have tried loading the following subs:

http://www.labibliotecadeserta.com/solaris(1972)eng.srt

I have tried with other subs, but these are the most accurate ones.
The problem is that, way into the film, the subs start to show randomly (VLC shows one line and then ignores 3-4 lines to then show another random line), I tried saving the subs in other formats, but the problems persists.

The version of VLC that I'm using is 0.8.6c, I know it's an old one, but since I am using Ubuntu Gutsy, I can't upgrade without having to download dozens of new libraries, and compile them all.

I think there should be a way to fix this, since I have tried other subs in other films and they work flawlessly.