I’ve just switched my host application from Vegas 7 to Vegas 10. Since then, I’ve experienced such problems importing avi and mov formats. For about 2 to 3 days of research, I’ve learned some stuffs about aviplug.dll, ffdshow, error report system delete, etc..but all of them didn’t work for me. Now I intentionally did not include k-lite codec pack cause this one was the main thing for me. At first, I had the k-lite codec pack installed on my system since Vegas 7 until Vegas 10. Fortunately Ive come to think to maybe find something the same stuff that must be updated this time and I WAS RIGHT. I replaced the k-lite with the new one, K-lite codec pack 9.3.0 Final(windows) and it WORKS like a charm. No need to touch anything in Vegas 10. Hope this will work for you good luck.