slow sync and disc errors

i have an ipod classic and i use windows.

last week, i plugged my ipod in to sync a few new albums and while it was plugged in (which automatically launches itunes and automatically begins the syncing process,) windows disc check popped up.

it didn't find any errors, but something about the sync/disc check happening both automatically at the same time caused my library to vanish.

when plugged into itunes again, it showed 2x my regular space used and an error message popped up saying i was 3gb over space limit.

i decided to just restore the ipod and start from scratch.

now, i know syncing takes a stupid long time because of the first time i loaded it--i have 18,000 songs and i compress everything so i know the sycn will take a long, long, long, looooong time.

i began the new sync at 8am the previous day. i let it sync for about 40 hours, at which point it said only 8000 of the 18000 songs had been loaded.

at that point, my computer had a crash and restarted. while the ipod was disconnected, i checked it and saw that it only had 52 songs on it. bear in mind it only had 52 songs after 40 hours of sync time.

when the computer restarted and the ipod was plugged back in to resume syncing, disc check popped up again, and once again found no errors.

itunes resumed the sync but started from the same point as before--none of the claimed 8,000 songs were actually loaded, even tho itunes said so before the crash. it has been syncing for the past 6 hour but now "itunes is not responding" and i cannot open the window to see what is what.

why is everything acting so buggy?

should i let the (presume) syncing continue in the "not responding" instance of iTunes or should i kill the process and start again?

why does windows bring up the disc check window so often all of the sudden? is it because itunes freezes and doesn't properly eject my ipod?

is it common for compressed syncing of that many songs to take so long? i have calculated the process to take roughly 72 hours--roughly one song takes about 15 seconds to load.