Why does "Chopper XP" read every file as an .iva?

[Binary Wolf]

No matter what VOB file I try to open with "Chopper XP," v2.7, the app always reads it as an unsupported .iva type. But Chopper XP manually extracts a clip from a VOB without any problem. Tools like MediaInfo identifies the VOBs as containing MPEG-2 files. Is this problem a known bug or am I overlooking something?