Try reseting the Project properties., ie HDV is Pal or NSTC, it runs at the right speed ie., frames per second either 25 fps or 30fps.
You should not have to render the clips, but, if there is a red line above timeline needs to go to green. But, may not effect audio.
Good luck !!!!!!We use a Canon HV20 which is HDV (PAL) 25fps and there are no problems with sound in Premiere Pro. We have found the sound is somtimes dodgy out os sync using mov.H.264 files out of a Canon EOS 5D mark II which was running at 30fps, Canon have changed this now by Firmware 2.0.4 to run at 25fps.
Try changing Speed/Duration on some clips and Tick “Maintain Pitch”
Australia