Contacts syncing with Gmail

After i updated my os to 10.5.3 my address book app had an option to sync with my Gmail account. I turned that feature on, and all email contacts i had in my gmail account were uploaded to my iphone the next time i plugged it on my computer. My address book app doesnt show my gmail contats, and i cant get rid of them all at once in my iphone. There's def something wrong w that feature.

Btw, has anyone ever noticed how sometime, new contacts add in the iphone never shows up in the address book?