It's part of the main quest so can't really be missed. You have to complete the plot related quests at Porth Llaffan first, until a ferry service is opened. This ferry will take you to Slurry Quay, and Dourbridge is only a short distance East from there.
Outside the heights of Loneliness. This is East of Dourbridge and North of Bloomingdale on the left side
(Possible spoiler) folow the path south from the dourbridge region
He is in the big tent in the north-east corner of Dourbridge.
Slurry Quay is the little docking area west of Dourbridge, you are taken there when you are done at Port Llafan.
If you've reached Dourbridge, the Heights of Lonliness are atop the nearby mountains. You will see a cottage at the base.
That doesn't sound right, your copy of the game might be corrupt. See if you can take it back for a replacement.
They are East of Dourbridge.
East of Dourbridge is Hieghts of Loneliness
With a strength ring and corundum. I forgot where to get strength rings but i know that corundum is north of dourbridge on the east side a little waterfall
No, Dragon Quest IX is exclusively a DS title.
It's inland (east) from Slurry Coast.
I've heard Ram Raiders drop them, although all I get from those guys are sleeping hibiscus...you can buy them at some place called Dourbridge, too (wherever that is)