not sure why the dynamic themes and Playstation Mobile games wouldn't work for you if you copied them down correctly, but the PS+ trail can only be redeemed once per user. If you've used a PS+ trial before, it wouldn't work.
The code for the Vita game beta wont work until after August 21st, when the beta begins.
Codes on this account come up invalid for music unlimited and plus.
I am a plus subscriber currently and have been since the start. I have never used a free trial before. The SAME codes that wont work on this account DO WORK ON OTHER ACCOUNTS. Hence, I will assume that anyone that has had Plus or has Plus will get this invalid code error.
Also, some codes only work when you put them in ALL CAPITAL LETTERS.
Just some things nobody has really mentioned.
@jokerx79, have you ever had Plus? If so that code will always come up invalid.