Problem with un-jailbreaking

Ok so I have a slight problem with unjailbreaking my phone. I just un jailbroke it simply because I didn't find anything useful on it.
Anyway, to resolve any future conflict with Apple Care, I have a slight feeling that some of the jailbreaking files are still on the phone.

Before I jailbroke it, I plugged it in to iTunes and it backed it up as usual.
I then jailbroke it, everything was fine... but I noticed when I jailbroke it my carrier name showed up in a lower resolution for the retina display, same resolution as the old iPhone. I must have downloaded an old carrier file or something.

Now, yesterday I restored the phone, and I couldn't find the backup which I saved a few weeks back before jailbreaking my phone. I restored it to the latest copy (which was yesterday) and now I can still see that the carrier name is still in low resolution [leading me to believe that jailbreaking files haven't been erased].

What is the best thing for me to do? I still want to keep all my folders and app data intact.

Thank you for your help.

Jack