From DBZ vol. 2

Muten Roshi says the Saiyans arrived earlier by more than a month. Is this accurate?
From DBZ vol. 11

Here, Kami is talking with Kaio about resurrecting the people killed by Vegeta and Nappa.
In here, he make it sound like the "One Year" rule works only if you want to revive a multible ammount of people.
From DBZ vol. 17

Did Vegeta really calles Goku "Goku" instead of Kakarotto? Or is this an error from the translator?
One last thing from DBZ vol. 17.
In the page where Trunks is powering up (Page 8 ), the printing quality looks so horrible!!
I have the third printing from March 2007. Did they improve the quality in later prints?