Page 239, do you mean?
I'm not sure where, but we had found a warning of that sort (it's actually a fairly recent addition to TO's coverage; we have two earlier editions that both say "The site is close to the CV railway... making a visit to the area relatively swift, painless and rewarding") prior to our mid-morning visit, back in September 2002.
As a result we'd arrived with a pretty good idea of the route from the station, and were happily on our way, only to then have a succession of people stop us in the street and to proffer directions to the site!
(There are however three stations in Torre Annuziata, and I've only seen two of them. It's just possible, I suppose, that the third is located in a less pleasant area than the others?)
And as for our trip to Boscoreale last week... one of the station staff went to great lengths to make sure we understood the path to follow from the newly-opened station there, which involved a heavily signposted walk of a little over a mile.
As we'd bought daylong Unicocampania tickets we decided to take the bus back and - bless - were offered a lift to Pompei by one of the residents of the estate in which the site's set, after we'd been waiting a while - although (as he came over to point out to us, when he came back again and found us still there) we were too foolish to accept. When the bus did finally arrive, the driver was kind enough to divert off to drop us a little closer to the station - and then had to do a huge U-turn in the road to get back to his proper route.
It's experiences like those that make me mad when ignorant TA members write so badly of the people of Naples and its surroundings!
Peter