Problems with 3gp files and showimg

I’m a debian Sid user and use showimg as a viewer for all my photos and videos.
I have kplayer also installed and use the kplayer part for viewing videos in showimg.
So basically I can run showimg /path/to/files
Then it launches and gives me thumbnails of all my photos, home videos or films depending where I point it.

So anyway, I installed both kplayer and showimg (via one-click-install cos I couldn’t find any repos).
Although my films and some of my home videos play fine within showimg, any taken from my phone (3gp) refuse to play in showimg.
Though they play fine in other media players, including kplayer itself if launched seperately.

They play just fine within showimg on debian.

Anyone know what’s going on?