Since IOS 7 I have not been able to sync all of my songs.

Question

I have had nothing but issues since I downloaded IOS 7, I am fairly computer literate but I cannot solve this particular problem.
After the new system wiped everything off my Iphone, without warning, I had to sync everything again, it all worked, eventually, except the music.
I have and Iphone 4s, 64gb. and basically just use it for a phone and music (no videos as space is needed for music.)
The main issue was the amount of time it was taking to sync about 10k of songs, (longer than normal which was about a 1000 songs an hour) it seemed to hang whilst waiting for changes to be applied which took 45mins to an hour before it started syncing songs then would just stop syncing after maybe a couple of thousand songs, and then when starting again I would find that there were no songs on the iphone and it would start from the begining again. After a couple of frustrating days I restored my iphone back to factory settings, uninstalled Itunes from my laptop and after downloading Itunes again I set it up as a new phone. I thought this was working and the next day after a night of syncing it all looked good as it indicated it had finished and the desired 10k of songs showed up in the blue section of the sync bar with 20gb free (which was what is was in the past). However later I found that there were only 6k of songs on the Iphone.
After many tries it simply will not transfer anymore despite it indicating that during the sync that it shows 6k of songs then the bar it increases to 10k just before it commences the downloading stage of the sync (and again it seems to stall at the "waiting to apply changes" part of the sync).
Ok over to the Brains Trust!

Answer 1

I have done this on numerous occasions but I think that my Iphone has a defect. After many tries, reinstalls, deletion of content, changing content to be stored on external hard drive, deleting itunes and cleaning computer I managed to get all of the songs on and things seemed okay for a while.
The problem returned about a week ago after downloading a new album from Itunes. I now have 12.5k of songs leaving 10gb spare on Iphone which should be more than enough room to operate properly. Last night it seemed to be dowloading ok (after doing all of the above again for the umpteenth time) this morning it revealed that it had just synched 2.5k of songs and 18gb of "other" on the contents bar. it wont synch now as it says its over capacity. So the 18gb of "other" would probably be corrupted data that means it must corrupt each song as it tries to synch it.
The 2.5k of songs it did synch are working on the Iphone as is every song in the library on Itunes. I did completely delete the new album I bought and redownloaded it from the store then tried to synch just that album and it worked fine.
Just about time to dump apple I think!