Error message when connecting 80GB Video iPod

Question

I'm getting this error message when trying to connect my 80GB Video iPod:
"The iPod (name) cannot be synced. An unknown error occurred (-48)."
Never seen this one before.
I haven't synced this iPod for a few weeks but it always behaved fine before, taking a few seconds to appear in iTunes (v7.5) then syncing perfectly when I hit the Sync button (I have it set to manually sync only because sometimes I want to change the contents or only sync music).
Before syncing on this occasion, I did an iPod software update via iTunes - iTunes said there was a newer version (1.2.3). After the update, I disconnected the iPod for a few minutes (somehting I wanted to check content before syncing), then reconnected it. At first iPod took about a minute to show up in iTunes - way too long. I Reset the iPod and tried again but still LONG delay to appear in iTunes (again about 1 minute). I did another Reset - same result. Then I did a complete Restore, after which syncing to restore the contents gave problems - it refused to finish the sync. I had to disconnect and start again, syncing the data one section per sync session - Contacts, music, videos, iCal - which seemed to work fine. Then I disconnected, waited a few minutes then reconnected the iPod to check. It wouldn't connect at all. Did a Reset, tried o connect again and it did connect but then proceeded to resync all my contacts taking almost 30 minutes (way too long) to do so (I had made NO changes in Address Book since that data was put in there). I tried to reconnect again but then got the error message (above). Did another total Restore and the same shenannigans happened. Now, I have an iPod with data on it and works fine, but iTunes won't recognise it - just gives this error message every time.
By the way, my 8GB Nano (software 1.1.3) seems to sync fine on the same system, same computer.
Could this be the 1.2.3 iPod software giving issues? I appreciate any help because I also use this iPod for recording for my work, which getting a little urgent now.
Many thanks.

Answer 1

Thanks Zevoneer, but no real success. I did all that but when I tried to sync after it, it got partially through the sync (about 10% I'd guess) and presented an error message saying that the disk couldn't be read form or written to (sorry but I forgot the error number). I disconnected the iPod, waited a few minutes then reconnected and again got the message but then the ipod continued to finish the sync, even though almost all of the music and 2 of my 4 videos didn't go over to the iPod. I'm now thinking that this just isn't satisfactory reliability from the device since I use it a lot in my work and rely on it. But this new iPod is only a few months old, had very little use and only made about 12 recordings - In comparison, I've used the Nano heaps but now want to move over to the bigger one, basically for more capacity and bigger screen for video. I wonder if it's a hard drive failure in this iPod?
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