I try to capture hdv video but it will not detect scenes; "eneable hdv scene detections" in capture properties is on??? any thoughts...

This is probably not the answer that you are looking for but I just use Cineform's NEO HDV and it takes care of all that. I also shoot in 24p with my HV20 and it can get complicated to work around but the NEO HDV takes care of pulldown removal too, (all that at the same time). Works perfectly.

Only downside is the price tag of $249.