Anyway, what version you using? I compiled r3585 with different Qt versions and don't exactly mark what is using what. Unlikely but maybe the Qt version is the problem.
Try this one:
http://sourceforge.net/projects/smplaye ... e/downloadSMPlayer r3590 compiled with QT 4.7.0 and MPlayer r32198.
I tried all my .mp4 files that use the 'ffh264' codec and had no issues. Sherpya has a newer MPlayer build available but I deemed it unfit just because of an aspect ratio problem with one of the videos I tested;
http://oss.netfarm.it/mplayer-win32.phpI kept all the anime/Japanese dramas I downloaded for some time and other videos so I have a bit of a selection to test with.