iTunes Authorization

I have a bit of a problem and I am not sure how to fix it. I have a iPhone, iPad and an old video iPod. My problem it with iTunes, however. A little back story- I had an original user ID with Apple. This was before you had to tie it to an email to work. Then when iPhone 4 came out, you pretty much had to move to an email. I was able to consolidate my user ID over to my email. Everything was fine- or so I thought. I have music match, so I can move my library back and forth. O.K., that’s the back ground- on to my problem.

My iPod is used in my car only. It’s plugged into my radio through the 30 pin connector. My car has been sitting so I needed to charge it. I figured since I haven’t synced it in a while, I’ll do that do. I hooked it up and wanted to sync my whole library over- I’ve done this many times. However, I got a pop up that said I have music on this iPod that I don’t have on my computer- would I like to move it over? I said yes and then it goes to a pop up that said this computer needs to be authorized to play this music. I sign in and it goes right back to the pop up. All of this music is music I bought with my old ID before I had to consolidate it with my email. I deauthorized my computer and authorized it again and it did the same loop. I went to my iPhone and iPad and found one of the problem songs and it plays fine there, no problem.

I’ve did my research and most problems seem to be fixed with deleting it and downloading it. However- it is saying 714 songs are not authorized. I don’t even know what any of them are or have anyway of finding out all of them.

Any thoughts?

Thanks ahead of time for help- I appreciate it!