Having just switched to a new PC I faced the same problem that bugged me for months with my laptop (before I found a fix and then lost it again) so, as much for me as for anyone else, here is the solution to not getting any audio tracks in Adobe Premiere CS3 when importing files from a Sony Handycam.
My particular model Handycam is a DCR-SR36 – although I believe the issue may affect other Sony Handycam models as well. The problem is that when you take video files from the camera into Premiere, you’re left with video only – and no audio track. The fix, as it happens, is quite a simple one and requires you to download this dll file (right click and save target) and copy it into the root folder of your Adobe Premiere.
Before you do, I take no responsibility for anything that goes wrong – but it worked fine for me on both computers for which I’ve tried it.
If you restart Premiere, you should find your video files now have sound.
On a related issue you may find that Adobe Premiere isn’t playing any sound at all through your speakers, even though you now have an audio track in the timeline. This can be fixed by navigating to: Edit –> Preferences –> Audio Hardware –> ASIO Settings
Then ensure that each device is checked (as they’re not all checked by default, so you may end up with no sound).
This is the double headed problem I just faced today (and again last year, but didn’t make a note of the solution) so the next time I get stuck on it, I’ll know where to go. Hopefully it’ll help someone else too.