zZzeta/S is away on holiday until next weekend, you can use PE Explorer and edit the Date Stamp (Tutorials - free cracked edition), and hex edit. I've not tried to login today yet as the F1 Monaco is on.
For those who say it is the injector.. I can use the knife hack fine with my injector. This hack is not working, even when it has been injected without error, it does nothing. My STG behaves the same, as does any other weapon.