This user complains about his collection of Shazam tags which has been deleted from the iPhone after the 2.2 upgrade:

THANKS apple for RUINING the best application available: SHAZAM. After the much touted “upgrade” 2.2 all the song tags have been deleted and the program no longer works. I was just sitting down to order the tagged songs for a present and the entire fu*cking list is gone MERRY CHRISTMAS. ITUNES has seen my last dollar…I will now order all my music from Amazon no matter how expensive or inconvenient it may be and you can be sure I’ll post and blog the hell out of this

Please note that it seems like there is a new version of Shazam available.