hey, I use Linux too (ubuntu)
and run video converter under wine.
i dont know why but lately it started popping up errors so I reinstalled and now it works perfectly except if doesn't output a file???

running in terminal shows nothing out of the ordinary except
'fixme:quartz:AVISplitter_ProcessStreamList fccType iavs not handled yet
err:quartz:Parser_Destroy pinref should be null, is 1, destroying anyway'
has this ever happened to you?
(btw i did set the file path right)
dw if you dont know anything about this kina thing,
I dont either