FCP 6 export to QT conversion for ATV is stretched. Help!

I hope someone can help. Around the middle of June I noticed all the files I was exporting from FCP 6.0.4 with QT conversion to Apple TV were ending up with a horizontal stretch. A get info shows a file dimension of 720x640 were as before the problem arose they where all 640x480 after export. I am using a Canopus ADVC-100 for input. Input is set to DV NTSC 48 non controllable device. The files that are imported are fine as well. I can open them in the Capture folder and they appear fine. I had done hundreds of files that exported correctly in April and May. Something changed in June. I have an 07 Aluminum iMac with 2.8 chip and 4gb of ram. I might add I tried a clean install of Leopard with QT version 7.3 and installed FCP with no updates and it does the same thing. I noticed that it seems any export through QT conversion now stretches the exported file, even with other formats besides Apple TV. I am converting several hundred old recordings on VHS tape to Apple TV.
Any ideas out there?