Your model lies quite far from the SU model origin point (more than 2 kilometers). As it is, a scaled export from a plan view worked OK, but the unscaled perspective view didn't. When I moved the model to the origin it worked OK.
Check out the key caps you have in the fonts you are using or possibly change fonts such you can find a symbol you want. You can use that to add symbols but not the exact one you have in the OP unless you want to make a special font. Look under start, programs, accessories, system tools and character map. For your fonts it will show the code to type for the selected symbol. Examplt http://sketchup.google.com/3dwarehouse/details?mid=2d79c340445bb6b89f30f02514717f00
