Updated Tags Don't show in iTunes

I used this one time like 3 days ago putting an explicit tag and tried the same today but everytime I try, it doesn't save. can anyone help?

How do you know?
Do you get an error message?

the reason i know is because it says saving tag 1 of 1 or something like that don't know because it happens really quick but i didn't get the pop up saying tag saved. and when i go to Itunes, the song didn't change

So it is an iTunes problem? What do the tags look like in MP3tag? Are they ok there?
As iTunes has its own database you would need to trigger the function that updates this database. One would be: delete the entry from iTunes and then import the file again. Also, there are scripts around that update the database with the data from the files.

can you open that specific music file in a music-playing program like WinAMP or VideoLAN.
Then, you can try to view the music file and see what tags you have saved/written.

MP3Tag can read/write APE and ID3 tags.
( so, in MP3Tag, Tools -> Opens -> Tags -> Mpeg see what tags are being written by MP3Tag )