Ok, a few days ago, I compiled mplayer again, using the source from the CVS this time. Everything seems to be fine, until I discovered a really strange problem when displaying greek subtitles in avi movies.
The Greek were sort of inverted horizontaly.
Instead of displaying:
"Τι κάνεις" it looked more like "ςιενάκ ιτ".
English were displayed fine, so "Τι κάνεις John" looked like "ςιενάκ ιτ John".
I tried using a windows arial.ttf font with the same results. What I had to do is keep the font encoding to Modern Greek (ISO-8859-7) but change the Subtitle encoding in Subtitle & OSD tab to Western European Languages with Euro (ISO-8859-15). I don't know why but after doing this it worked.