Exporter Error on Transcoding to Apple ProRes 422 with Episode 6.1.2

While trying to transcode a MPEG-2 MXF file into Apple ProRes 422 HQ using Episode 6.1.2 installed on my Mac OS X Snow Leopard system I received the following error message: “Exporter Error: No frames in Queue nr. 0.” What does this means? However, they do accept certain Mpeg file. But I cannot identify any difference between those that are accepted and not. Any help will be appreciated.
