after upgrading 1Password to 4.5b25 on my iPad mini (iOS 7.0.4) the 1Password icon on the lockscreen disappeared:
Problem does not occur on iPhone 5 with iOS 7.0.4
Thanks for the report @as3h! The lock screen on the iPad is still a work in progress so you can expect to see this problem resolved in an upcoming beta.
Happy to have you on board as a tester!