Arista files fail to convert when folder selected

When trying to convert files by selecting folder they fail to convert.
When selected individually, they manage to convert, the converted filesize (from the above original filesize) is 177.0 Mb.
Is this a possible bug?

Error!
Conversion of Filename.avi to Generic DVD Player DivX Home Theatre failed! Reason: Not a recognised media file!

Original filetype
Filesize..366,4Mb
Type...AVI

Video
Dimensions.. 608*336
Codec XVID.. MPEG-4
Framerate.. 24
Bitrate.. N/A

Audio
Codec.. MPEG 1 Audio, Layer 3 (MP3)
Channels.. Stereo
Samplerate.. 48000 Hz
Bitrate.. 133 kbps

Type to convert to

GENERAL
Video Conversion Pre-set
Short name.. dvd
Description..DivX or MPEG2 for DVD players
Make..Generic
Model..DVD Player
Preset name..DivX Home Theater
Author name..Daniel G. Taylor
Author <email address hidden>
Version..1.2
Container..AVI
Extension..avi

VIDEO OPTIONS
Video Codec..MPEG4/DivX/XviD
Codec Options..pass=quant quantizer=5 max-bframes=0 trellis=true
Width..320 - 720
Height..240 - 480
Framerate..1.00 - 30.00
Effect..None

AUDIO OPTIONS
Audio codec..MP3
Codec options..bitrate=160
Channels..1 to 2