Aspect ratio changed after capturing. What's wrong?!
 

I had a weird problem here. I shot my footage in HDV mode using my XH-A1 and capture them using Vegas 7. The 1st few tapes were problem free. However for the last few tapes, their aspect ratio went haywire. The video are stretched to become 4:3 instead of the original 16:9. I set my project setting to HDV-720-25p (1280 x 720). Some video doesn't seems to auto adjust to become 16:9 and remain as stretched 4:3, whereas some will auto adjust to fit it.
In another words, I have
(1) problem free video working fine
(2) stretched 4:3 video remain as stretched 4:3 no matter what project settings I set
(3) stretched 4:3 video remain as 4:3 when project is in DV Pal, becomes 16:9 when set to HDV 720.

Anyone know what's wrong with it? Did I capture wrongly in the first place? I never had this kind of problem before. Please help me. Thanks.