Hey Sassan,
here is what I learned last week:
"slightly off"
can mean too far left/right or too far up/down.
too far left or right ---> amend your SCP alignment. Because this means, the mount looks too far east or west.
or
too far up ---> the latitude in the mount itself is set too high ( the tube points above the actual location of the star because it assumes standing further south from the equator)
or
too low (the tube points below the actual position of the star because it assumes it is standing closer to the equator.)
(Don't overly trust the latitude wheel in the mount head. They're not accurate.)
or
the mount might not be leveled properly. Don't trust the bubble level in the mount head. Use a real builders bubble level.
Silv