I was out for a ride today and noticed my bb had loosened about 1/5" from the shell on the drive side. It's a square taper cartridge bb, Italian thread. When fully installed the drive side cup doesn't sit flush with the shell -- as in it's a bit aslant. The rear has about a 1mm gap; the front contacts the shell.

So what's the deal here, and what should I do to fix the issue? Should I just crank down real good on the drive side cup to secure it? Would a cup and cone unit be more secure? I'd prefer not to have the bb faced if possible. Thanks.