Is the damage on one side only? Is it on the side facing the sun? If it's only on one side, maybe you could have a look at this other thread: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=77289
Thanks for your replies, they have helped me figure out what to do. The easiest and fastest thing to do seems to be to replace this tree because it is a specimin tree in the landscape and I'm doing that today. :)
Is your bark mulch being allowed to get right up beside the trunk? This may have contributed to your problem. Be careful about planting another tree in the same spot in case there is an existing problem with the soil :)
Thanks, we're going to put disease and pest control stuff all around the spot just in case. But the tree was only there for 10 months and the trunk has huge wounds that we didn't notice because of the foilage when we bought it - didn't think to look under the canopy at the trunk! Live and learn.