After switching to full screen there are two different things that happen to the subtitles (at least with mkv files).
The video screen ratio was 4:3 and the screen is 16:9 so there are black bars on the left and right.
1) The subtitle text is scaled so big that it does not fit the screen anymore. It looks like the size would match if i would shown on the hole 16:9 screen but only the part on the 4:3 video is shown so the left and right part of the subtile is cut off. Looks like the size vor subtile is calculatet from screen width and the black bars left and right are drawn over the subtitles. The subtitlesize should be calculated from the videowidth on the screen not frim screenwidth especialy if you watch 4:3 videos on an 16:9 screen.
Even if it would show the hole subtitle the text is realy big a choosable max. fontsize would be fine.
2) The subtitle text is not shown at all.
In the Windows version all works fine.
Problem 2 does not appear and Problem 1 cannot be tested (I only have a normal 4:3 TFT). So seems a problem with the linux version and the framebuffer.
System: PS3
Videodevice: EPSON EMP-TW1000 (Full HDTV Beamer)
OS: Yellowdog 6.0
VLC Version: Each tested version including 0.8.6h
Repeatable: Yes (every time)
File: can be send if required