LTO4 drive with possible issues

All,

We're having some tape issues with our Windows servers backups to LTO4
tape. We're trying to figure out if the issue is some of the tapes or the
drive.

Questions:

1) If I find someone else locally that has an LTO4 drive for Windows
backup, the tape should be compatible with that drive, correct?

2) If I find someone else locally that has an LTO4 drive for IBM i, the
tape would *not* be compatible with that drive, correct?

3) The backup software (Nova) has a Format option that I use to name new
tapes. Since that takes a matter of seconds, it's really just naming it
and doing some quick format to say "I'm an empty tape". Is there such a
thing as a true formatting of an LTO tape after it leaves the factory?

Thanks.