Petra: Thank you for answering this one!
I too have a T-mapper on Pacific so feel free to holler in general chat and we can set something up or send an im. A group get together sounds great! And even those who don't have a mapper would be welcomed, I think, to help kill and split the goodies. This gives us more of a reason to do many of them at once.
With mining all I do is use the enhanced client, open your T-Map and the large enhanced map. go to the general area of the red dot on the t-map.
compare the 2 and make a waypoint on the map. walk to the waypoint and maine at your feet. once you get an eye for finding the rough point on the world map you will
find that the mining bonus does the rest, the longest I have spent looking for a chest was around 45 seconds and I dont use screen shots or anything, just the enhanced client map zoomed right in and compare landmarks.
the picture on the t-map image in enhanced client is goo enough quality for a close look to e good enough to determain roughly where it is. Just make sure you right click the map and do dig for treasure. out of 7 maps i did last night I was standing on top of the chest on 5 of them, once you get into the habit you will be able to glance at the map and run right to the locastion.