Aspect ratio and negative buffer issue

[Eles]

Hi. PMS is almost perfect.
However, I cant solve two issues which prevent me to use it flawlessly and without being occasionally crazy.
The renderer is Philips TV (37pfl3507). I found the profile on this forum, it is properly recognized and I can browse shared media.

Aspect ratio:
When I play a streamed movie, the Philips TV shows it in an original aspect ratio (so usually as a smaller picture in the middle). And I have only two options - let it like that or press full screen button - the width and height are both scaled to the whole screen and a movie looses its original aspect ratio. Most of my movies are not 16:9, but they vary from 21:9 to even 4:3. I tried to put many commands to mencoder custom option window, but nothing has forced the movie to scale while keeping OAR. Could someone give me a tip? I have tried so many custom options found on the Internet or in this forum, and nothing worked for me. Either it didnt do anything with AR, or a movie wasnt played at all, or the TV showed "unsupported format".

Negative buffer:
Even when I want to watch windowed movies, sometimes after pressing the play button, the screen shows a movie name, then goes black and it stays like that - nothing starts. When I check the PMS status window, the "transcoding buffer status" shows negative values, like -1 billion MB. In that case I must quite PMS and then the temporary frozen TV starts to work again.
What is this caused by?

My movies are in so different formats and contain differently encoded audio and video tracks, so I didnt find any pattern in that. For example: two mkv files are played well and two arent - even if they all contain lets say h264 video and AC3 audio track.

[Eles]

Alright. The aspect ratio problem is solved: I found that this:

-vf scale=1920:-3

forces a video to scale width to 1920 and proportionally set the height with keeping the original aspect ratio. It didnt work with -1, but -3. I dont know why, but it doesnt matter now.

Now only that negative buffer value remains.

[negate]

not working whith 42pfl6007
ps3 172

any ideas? thanks