IPhone loses USB connection during sync

Question

My new iPhone is working fine so far except for one pretty major issue: I can't sync music/videos to it very well, because about 20/30 seconds into the sync, it loses USB connection. The "Sync in Progress" screen disappears and it goes back to the home screen, and I get an error message in iTunes that says "The drive cannot be found" or "The drive cannot be read from or written to"
The sync itself does work, because I tried syncing a playlist with only one song, and it worked fine because it had time to sync before the connection was lost.
I have USB 2.0 ports and my drivers are updated. I've tried every USB port on my computer.

Answer 1

I read your other thread and a couple of things struck me.
First, it wasn't clear to me whether you'd actually turned off auto sync and then gone in and disabled everything except for a movie or two, let's say. Because we have definitely seen issues where other sync aspects (particularly email) cause issues with media syncing. If you haven't tried it it's definitely worth a try (go into iTunes with the iPhone connected and turn off auto sync -- then hook up the phone and turn off all sync options. I'd then try a music playlist with an album or two. If that works turn off music sync and try with a video or two).
Assuming the above gets you nowhere (and trying to place myself in your shoes) if you lived here in the US (which I don't think you do) the easy no-brainer thing to try would be something like this:
http://www.bestbuy.com/site/olspage.jsp?skuId=7833785&type=product&id=1142298626 004
Since Best Buy offers a money-back return policy this is safe to try and only involves a bit of work in installing the card. But doing this will isolate the MB from the problem, as well as any drivers issues (since the drivers for the card should be okay).
In the old days this kind of solution (albeit with firewire cards) was recommended all the time with iPods, and it solved about 98% of all difficulties. I don't have any data (even anectdotal) here to back it up, but my feeling is this should solve whatever problems you're having. If not it would be valuable information as well.
Overseas I don't know what to tell you, but if there's anyone listening in on this thread from the states perhaps they can try this and let everyone know.