Welcome to the forum.
Can you provide some more info, like how you are Importing the footage, what is the file type and the specs of those files? That file size causes me to question your HDD formats too. Also, what does G-SPOT say about the files with the Audio drop-out. This ARTICLE will be useful to determine the types of info that will be very useful.
I'm importing the files from the camera via a USB cable into their own folder using windows explorer.It's a AVCHD file, around 2.075GB in size and about 16 minutes in duration. I also had this problem when using Premiere Elements. My other camera, a sony Z7U, has no problems like this. I'm on a dual quad core system, nvidia fx4800 vid card - the system is beefy, no issue there.
Does this Sony record Audio as DD 5.1 SS, or 2-channel stereo AC3?
For your PrPro, do you have the CS4.2.1 update?
This thinking here,
I have it set up for stereo, the documentation is not clear regarding AC3. I run the clip in windows media player and I miss the last 1/2 second of audio there, also. I'm running PPro 4.2.1. For the sequence presets, I'm set at: AVCHD, 1080i30 anamorphic (I'm assuming non-square pixels out of the sony handicam).
Dan Powers Photo
What does G-Spot say about one of the Clips, that has no Audio?
If WMP is not picking up all of the Audio, and PrPro is not either, then it seems that something is amiss with the transfer of the files.
Good luck, and please let us know.
I think the problem is due to the clip spanning. When the camera hits the 2 gig file limit, it simply continues to write to a new file, without regard to closing neatly out a GOP. When you import the second file, I think there's a GOP & audio buffer that's split between the two files. When you import the 2nd file, it doesn't know about the leftover data in the first file, and jumps ahead to the first complete GOP. Your A/V might be potentially out of sync, too.
The only thing I can suggest is to try to use something like Sony's ClipBrowser to see if you can have it consolidate the media to an unsplit file, or something like that.