Scar, this has been widely discussed in the "streching video" post. What happens : mplayer is in "embedded" mode in canola, and due to a bug, it wasn't able to figure out correctly the format, thus stretching the video. There were hacks we could do (open mplayer 2 times) but we decided to patch (small fix) mplayer to work correctly, we did we submited to mplayer and we are waiting to it to be applied.
About performance, there's also a loss (thus for example any media player that embedds mplyaer will have a slightly worse performance than the real mplayer. We are actually not changing confs etc. Scar: do you have n810 ? if so have you already formatted your internal disk ? Marcelo