I thought you were intendingto start a new thread. It'll probably give you more help than adding to existing ones. If you do decide to start a new thread, go here;
http://discussions.apple.com/forum.jspa?forumID=1208&start=0 and select *Post new topic* just above the table of posts.
Anyway, presumably, the 10GB of space being used on your iPod is listed as
Other. I think, from what you've said about your friend's version of iTunes and so on that your iPod has become corrupted. The only way (that I know of) out of this is to connect it to your iTunes and
Restore it, from the
Summary pane.
For future reference, iPods can only be
Synced with one library and I think the default is that iTunes will automatically detect an iPod connected to it and perform a
Sync. Even if it isn't, connecting it to someone else's iTunes, especially if their version is older than yours is never a good idea. If your iPod has been
Synced with iTunes 10, or it has a version of the iPod software that requires something newer than the other computer has, you can almost guarantee problems if you plug it into the older machine.
To answer the question you asked someone in the other thread you joined, we're fellow users, not Apple employees. Ocassionally, Apple employees do contribute to threads (they have an Apple icon in the poster information on the left), but it is only ocassionally. The volume and diverstity of issues posted on these forums mean that users are better suited to helping each other out while Apple employees watch, learn and if required, then (behind the scenes), they fix any issues with their software.
Phil